Bottle

A tubular bottle is formed of a synthetic resin material having a bottom part. A bottom wall part of the bottom part includes a grounding part located at an outer circumferential edge thereof, a standing peripheral wall part which is connected from a radial inner side of the bottle to the grounding part and which extends upward, a movable wall part that protrudes, from an upper end of the standing peripheral wall part, toward the radial inner side, and a depression peripheral wall part that extends upward from an inner end of the movable wall part in a radial direction of the bottle. The movable wall part is arranged so as to be movable upward centering on a portion connected to the standing peripheral wall part. An upward swelling part is formed at an outer end along the radial direction of the bottle of the movable wall part.

TECHNICAL FIELD

The present invention relates to a bottle.

Priority is claimed on Japanese Patent Application No. 2011-187491, filed on Aug. 30, 2011, the contents of which are incorporated herein by reference.

BACKGROUND ART

Conventionally, as a bottle formed of a synthetic resin material in a shape of a bottomed tube, as set forth in, for instance, Patent Document 1 below, a bottle having a constitution in which a bottom wall part of a bottom part includes a grounding part that is located at an outer circumferential edge, a standing peripheral wall part that is connected from a bottle radial inner side to the grounding part and extends upward, a movable wall part that protrudes from an upper end of the standing peripheral wall part toward the bottle radial inner side, and a depression peripheral wall part that extends upward from a bottle radial inner end of the movable wall part has been known. In the known constitution, the movable wall part rotates about a portion connected to the standing peripheral wall part so as to cause the depression peripheral wall part to move upward, and thereby a pressure reduced in the bottle is absorbed.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Means for Solving the Problem

However, the conventional bottle leaves room for improvement in increasing performance of absorbing the pressure reduced in the bottle.

Here, to increase the reduced-pressure absorption performance, it is necessary to secure an amount of upward movement of the movable wall part. To do so, at the portion connected between the movable wall part and the standing peripheral wall part, it can be taken into account that an angle (angle of depression) between a tangential line of the movable wall part and a horizontal plane is increased, for instance, to about 45 degrees with respect to the horizontal plane, and that the movable wall part is formed to be located as low as possible. However, in this case, it is easy to secure the amount of upward movement of the movable wall part, but there is a problem in that it is difficult for the movable wall part to move upward.

Accordingly, the present invention has been made in consideration of these circumstances, and an object of the present invention is to provide a bottle in which improvement in performance of absorbing a pressure reduced in the bottle is attempted to allow a movable wall part to move smoothly.

Means for Solving the Problem

To solve the above-mentioned problem, the present invention proposes the following means.

According to a first aspect of the present invention, a bottle that is tubular, is formed of a synthetic resin material, and has a bottom part. A bottom wall part of the bottom part includes a grounding part that is located at an outer circumferential edge thereof, a standing peripheral wall part which is connected, from a radial inner side of the bottle, to the grounding part and which extends upward, a movable wall part that protrudes from an upper end of the standing peripheral wall part toward the radial inner side of the bottle, and a depression peripheral wall part that extends upward from an inner end of the movable wall part in a radial direction of the bottle. The movable wall part is disposed so as to be movable upward centering on a portion connected to the standing peripheral wall part along with the depression peripheral wall part. An upward swelling part which swells upward is formed at an outer end along the radial direction of the bottle of the movable wall part.

With this configuration, when the movable wall part moves centering on the portion connected between the movable wall part and the standing peripheral wall part, the upward swelling part becomes a starting point when the movable wall part moves for the first time. In this case, the upward swelling part begins to move upward depending on a change in an internal pressure of the bottle. Thereby, in accordance with the movement, the entire movable wall part moves upward. As a result, it is possible to smoothly move the entire movable wall part depending on the change in the internal pressure of the bottle.

Accordingly, in the portion connected between the movable wall part and the standing peripheral wall part, even when an angle (depression angle) between a tangential line of the movable wall part and a horizontal plane is increased to improve the reduced-pressure absorption performance, it is possible to inhibit difficulty in the upward movement of the movable wall part. As a result, it is possible to improve the performance of absorbing the pressure reduced in the bottle and then to smoothly move the movable wall part.

Further, a downward swelling part which is recessed downward may be formed in the movable wall part at a position where is at more inner side in the radial direction of the bottle than the upward swelling part.

In this case, a length from an outer end to an inner end of the movable wall part in a radial direction of the bottle is longer than a tangential length of a virtual line that extends along a surface shape of the movable wall part connecting an inner end of the standing peripheral wall part in the radial direction of the bottle and an outer end of the depression peripheral wall part in the radial direction of the bottle. Thereby, it is possible to secure an amount of movement of the movable wall part and to further improve the reduced-pressure absorption performance.

Advantageous Effects of Invention

According to the foregoing bottle, the improvement in the performance of absorbing the pressure reduced in the bottle is attempted to allow the movable wall part to move smoothly.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a bottle according to an embodiment of the present invention will be described with reference to the drawings.

As shown inFIG. 1, a bottle1according to the present embodiment includes a mouth part11, a shoulder part12, a trunk part13, and a bottom part14, and has a schematic constitution in which these parts11to14cause respective central axes thereof to be placed on a common axis, and are continuously connected in this order.

Hereinafter, the common axis is referred to as a bottle axis O. In the direction of the bottle axis O, a side of the mouth part11is referred to as an upper side, and a side of the bottom part14is referred to as a lower side. Further, a direction perpendicular to the bottle axis O is referred to as a radial direction, and a direction going around the bottle axis O is referred to as a circumferential direction.

The bottle1is integrally formed of a synthetic resin material by blow molding using a preform formed in a bottomed tubular shape by injection molding. Further, a cap (not shown) is mounted on the mouth part11. Furthermore, each of the mouth part11, the shoulder part12, the trunk part13, and the bottom part14has a circular shape when viewed from a cross section perpendicular to the bottle axis O.

A first annular groove16is continuously formed in a portion connected between the shoulder part12and the trunk part13throughout the circumference of the connected portion.

The trunk part13is formed in a tubular shape, and between opposite ends thereof in the direction of the bottle axis O, a diameter thereof is smaller than those of the opposite ends thereof. A plurality of second annular grooves15are continuously formed in the trunk part13at intervals in the direction of the bottle axis O throughout the circumference of the trunk part13.

A third annular groove20is continuously formed in a portion connected between the trunk part13and the bottom part14throughout the circumference of the connected portion.

As shown inFIGS. 1 to 3B, the bottom part14includes a heel part17whose upper end opening is connected to a lower end opening of the trunk part13, and a bottom wall part19which closes a lower end opening of the heel part17and whose outer circumferential edge serves as a grounding part18, and is formed in a cup shape

A fourth annular groove31is continuously formed in the heel part17throughout the circumference of the heel part17. As shown inFIG. 1, a radial depth of the fourth annular groove31is equal to that of the third annular groove20.

As shown inFIG. 3A, the bottom wall part19includes a standing peripheral wall part21that is connected to the grounding part18from a radial inner side and extends upward, an annular movable wall part22that protrudes from an upper end of the standing peripheral wall part21toward the radial inner side, and a depression peripheral wall part23that extends upward from an inner tip of a radial inner end22aof the movable wall part22.

As shown inFIG. 3A, the standing peripheral wall part21is reduced in diameter from a bottom to a top.

The movable wall part22is formed in the shape of a curved surface that protrudes downward, and gradually extends downward from the radial outer side to the radial inner side. This movable wall part22and the standing peripheral wall part21are connected via a curved surface part25that protrudes upward. Thus, to cause the depression peripheral wall part23to move upward, the movable wall part122is formed so as to rotate (move) freely around the curved surface part (a portion connected to the standing peripheral wall part21)25and cause the depression peripheral wall part23to move upward.

Here, an upward swelling part32swelling upward is formed at a radial outer end22bthereof, that is, at a portion adjacent to the curved surface part25in the movable wall part22. This upward swelling part32is formed in the shape of a curved surface that protrudes in a normal direction of the movable wall part22, and is formed in the shape of a ring that extends over the entire circumference of the circumferential direction. To be specific, the upward swelling part32is located above a virtual line L (e.g., a downward inflated curved line or a straight line) that extends along a surface shape of the movable wall part22connecting a radial inner end of the curved surface part25and a radial outer end of the depression peripheral wall part23. Further, the top of the upward swelling part32is located below the curved surface part25. In addition, an angle (depression angle) θ1between a tangential line and a horizontal plane at a radial outer end of the upward swelling part32may be set to be smaller than 10 degrees or more with respect to an angle (depression angle) θ1between a tangential line and a horizontal plane at a radial outer end of the virtual line L. In the shown example, θ1is set to about 28 degrees, and θ2is set to about 44 degrees.

Further, a downward swelling part33which is recessed downward is formed at a position of the inner side of the radial direction than the upward swelling part32in the outer end22bof the movable wall part22. The downward swelling part33is formed in the shape of the curved surface that protrudes in the normal direction of the movable wall part22, and is formed in the shape of a ring that extends over the entire circumference of the circumferential direction. To be specific, the downward swelling part33is located below the above-mentioned virtual line L described above. In this case, the above-mentioned upward swelling part32is configured so that the radial outer end thereof is continuously installed on the radial inner end of the curved surface part25, and a radial inner end thereof is continuously installed on a radial inner end of the radial outer end of the downward swelling part33.

The upward swelling part32is formed with a smaller radius of curvature than the above-mentioned downward swelling part33. Further, when viewed from the longitudinal cross section in the direction of the bottle axis O, a length D1 of a tangential line from the radial outer end to the radial inner end of the downward swelling part33is formed so as to be longer than a length D2 of a tangential line from the radial outer end to the radial inner end of the upward swelling part32.

The depression peripheral wall part23is arranged on the common axis with the bottle axis O, and is gradually increased in diameter from the top to the bottom. A disc-shaped top wall24disposed on the common axis with the bottle axis O is connected to an upper end of the depression peripheral wall part23. A tubular shape having the top is formed by both of the depression peripheral wall part23and the top wall24. The depression peripheral wall part23is formed in a circular shape when viewed from the cross section. Further, the depression peripheral wall part23is configured so that an upper end of a curved wall part23a, which is formed in the shape of a curved surface protruding toward the radial inner side, is connected to the top wall24, and a lower end of the curved wall part23ais connected to an inclined wall part23cvia an indented part23b. The inclined wall part23cis gradually increased in diameter from the top to the bottom, and a lower end thereof is connected to the inner tip of the radial inner end22aof the annular movable wall part22.

In the present embodiment, in the heel part17, a diameter of a lower heel part27which is connected from the radial outer side to the grounding part18is formed so as to be smaller than a diameter of an upper heel part28which is connected from above to the lower heel part27. The upper heel part28is a maximum outer diameter part of the bottle1along with the opposite ends of the trunk part13in the direction of the bottle axis O.

Furthermore, in the present embodiment, a connecting portion29between the lower heel part27and the upper heel part28is gradually reduced in diameter from the top to the bottom. When viewed from the cross section, a shape of the connecting portion29extends from the top to the bottom in a linear shape.

When the pressure in the bottle1configured in this way is reduced, the movable wall part22rotates about the curved surface part25of the bottom wall part19in an upward direction. Thereby, the movable wall part22moves so as to lift the depression peripheral wall part23in an upward direction. In other words, the bottom wall part19of the bottle1is positively deformed when the pressure is reduced, and thereby a change in the internal pressure (pressure reduction) of the bottle1can be absorbed without deformation of the trunk part13. In this case, the portion connected between the standing peripheral wall part21and the movable wall part22is formed at the curved surface part25protruding upward, and thereby the movable wall part22is allowed to easily move (rotate) centering on the curved surface part25. For this reason, the movable wall part22is allowed to be smoothly deformed depending on the change in the internal pressure of the bottle1.

Especially, in the present embodiment, the upward swelling part32swelling upward is formed on the movable wall part22. Thereby, when the movable wall part22moves centering on the curved surface part25, the upward swelling part32becomes a starting point when the movable wall part22moves for the first time. In this case, the upward swelling part32begins to move upward depending on the change in the internal pressure of the bottle1. Accordingly, in accordance with the movement, the entire movable wall part22moves upward. Thereby, it is possible to smoothly move the entire movable wall part22depending on the change in the internal pressure of the bottle1.

Accordingly, even when the angle θ2 between the tangential line of the movable wall part22and the horizontal plane is increased to improve the reduced-pressure absorption performance, it is possible to inhibit difficulty in the upward movement of the movable wall part22. As a result, it is possible to improve the performance of absorbing the pressure reduced in the bottle1and then to smoothly move the movable wall part22.

Furthermore, in the present embodiment, since a downward swelling part33is formed at a position of the inner side of the radial direction than the upward swelling part32in the movable wall part22, the length from the radial outer end22bto the radial inner end22aof the movable wall part22is longer than the length of the virtual line L that extends along the surface shape of the movable wall part22. Thereby, it is possible to secure the amount of movement of the movable wall part22and to further improve the reduced-pressure absorption performance.

While the embodiment of the present invention has been described in detail with reference to the drawings, a detailed constitution is not limited to this embodiment, and includes a change in design without departing from the gist of the present invention.

For example, when viewed from a cross section, the shapes of the upward swelling part32and the downward swelling part33may be appropriately changed in design without being limited to the curved surface shape.

Further, the upward swelling part32and the downward swelling part33may be intermittently formed in the circumferential direction.

Furthermore, a plurality of downward swelling parts33may be formed in the radial direction. For example, the downward swelling parts33may be formed in a corrugated shape in the radial direction.

Further, the standing peripheral wall part21may be appropriately modified, for instance, may extend in parallel in the direction of the bottle axis O.

Furthermore, the depression peripheral wall part23may be appropriately modified, for instance, may extend in parallel in the direction of the bottle axis O.

Further, the synthetic resin material of which the bottle1is formed may be appropriately changed into, for instance, polyethylene terephthalate, polyethylene naphthalate, amorphous polyester, or a blended material thereof.

Furthermore, the bottle1may have a laminated structure having a medium layer without being limited to a single layer structure. This medium layer may include, for instance, a layer of a resin material having a gas barrier characteristic, a layer of a recycled material, or a layer of a resin material having oxygen absorbability.

In addition, in the embodiment, the shape of each of the shoulder part12, the trunk part13, and the bottom part14when viewed from the cross section perpendicular to the bottle axis O has the circular shape, but it may be appropriately modified into, for instance, a polygonal shape without being limited thereto.

In addition, without departing from the spirit of the present invention, the components in the embodiment may be properly replaced by well-known components, and the above-mentioned modifications may be appropriately combined.

INDUSTRIAL APPLICABILITY

According to the foregoing bottle, the improvement in the performance of absorbing the pressure reduced in the bottle is attempted to allow the movable wall part to move smoothly.

REFERENCE SIGNS LIST