bottle

Abstract

To improve filling buckling strength.SOLUTION: In a bottomed cylindrical bottle 1 formed of a synthetic resin material, a bottom part 14 comprises: a bottom wall part 19 where a ground part 18 is located at an outer peripheral edge part; and a cylindrical heel part 17 that extends toward the outside in a radial direction as it goes up from an outer peripheral edge 18b of the ground part, and is formed in a curved shape toward the outside in the radial direction. A plurality of recesses 21 reaching a lower end part of the heel part across the outer peripheral edge of the ground part from a portion separated outside in the radial direction from an inner peripheral edge 18a of the ground part, out of the ground part are provided at even intervals in a circumferential direction. A bottom face of each of the recesses has a rectangular shape extending in the radial direction as viewed from a lower side. When intervals each in the circumferential direction of upper end parts located at the heel part are represented by A, and a size in the circumferential direction of an upper end part on the bottom part of each of the recesses is represented by B, out of the bottom face 22 of the recesses adjacent to each other in the circumferential direction, 1.0<A / B<3.2 is satisfied.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a bottle. [Background technology]

[0002] Conventionally, as a bottle formed of a synthetic resin material into a cylindrical shape with a bottom, as shown in Patent Document 1 below, for example, a configuration has been known in which the bottom comprises a bottom wall portion with a ground contact portion located on the outer periphery thereof, and a cylindrical heel portion extending upward from the outer periphery of the ground contact portion and formed into a curved surface protruding radially outward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5349780 Summary of the Invention [Problem to be solved by the invention]

[0004] When an attempt is made to reduce the weight of the bottle, there is a risk that when a large compressive load is applied to the bottle in the vertical direction, the bottom will be more likely to deform, with the lower end of the heel being drawn radially inward between the bottom wall and the ground contact surface.In this case, bending that extends radially, for example, will be more likely to occur in the part of the bottom wall that is located radially inward from the ground contact surface, making it difficult to ensure the so-called filling buckling strength.

[0005] The present invention provides a bottle that can improve filling buckling strength. [Means for solving the problem]

[0006] A bottle according to one aspect of the present invention is a cylindrical bottle with a bottom made of a synthetic resin material, the bottle comprising: a bottom wall portion having a ground contact portion located on an outer periphery thereof; and a cylindrical heel portion extending radially outward as it moves upward from the outer periphery of the ground contact portion and formed with a curved surface protruding radially outward, the bottom portion having a plurality of recesses equally spaced apart in the circumferential direction, the recesses extending from a portion of the ground contact portion radially outward from the inner periphery of the ground contact portion across the outer periphery of the ground contact portion to a lower end of the heel portion, the bottom surfaces of the recesses having a rectangular shape extending radially when viewed from below, the circumferential distance between upper ends of the bottom surfaces of the recesses adjacent to each other in the circumferential direction that are located in the heel portion being A, and the circumferential size of the upper ends of the bottom surfaces of the recesses being B,

[0007] The bottom portion has a plurality of recesses that are equally spaced circumferentially, extending from a portion of the ground contact portion radially outward from the inner peripheral edge of the ground contact portion across the outer peripheral edge to the lower end of the heel portion. This allows the heel portion and the ground contact portion to deform with little variation over their entire circumferential length, even if the bottom portion deforms such that the lower end of the heel portion is pulled radially inward between the ground contact surface and the bottom wall when a large vertical compressive load is applied to the bottle. This makes it difficult for the portion of the bottom wall that is radially inward from the ground contact portion to bend in the radial direction, and this, combined with an increase in the bottle's internal pressure, reliably improves the filling buckling strength. Since the aforementioned A / B is greater than 1.0 and smaller than 3.2, the packing buckling strength can be reliably improved. If the aforementioned A / B ratio is 1.0 or less, the width of the contact portion of the contact area that is located between adjacent recesses in the circumferential direction and contacts the contact surface will become narrower, and when a large compressive load is applied to the bottle in the vertical direction, stress will tend to concentrate at the contact portion, making it difficult to ensure filling buckling strength. ​When the aforementioned A / B is 3.2 or more, the width of the concave portion becomes narrow, and when a large compressive load in the vertical direction is applied to the bottle, stress tends to concentrate on the portion of the grounding portion where the concave portion is located, making it difficult to ensure the filling buckling strength.

[0008] The circumferential size of the concave portion becomes narrower or wider as it goes from the heel portion side toward the grounding portion side. When the circumferential size of the upper end portion of the bottom surface of the concave portion is B, and the circumferential size of the lower end portion located in the grounding portion of the bottom surface of the concave portion is C, it may satisfy 0.6 < C / B < 1.2.

[0009] Since the aforementioned C / B is larger than 0.6 and smaller than 1.2, the filling buckling strength can be surely improved. When the aforementioned C / B is 0.6 or less, the circumferential size of the portion of the concave portion located in the grounding portion becomes narrow, and when a large compressive load in the vertical direction is applied to the bottle, stress tends to concentrate on the portion of the grounding portion where the concave portion is located, making it difficult to ensure the filling buckling strength. When the aforementioned C / B is 1.2 or more, the circumferential size of the portion of the concave portion located in the grounding portion becomes wide, and the width of the contact portion that is located between adjacent concave portions in the circumferential direction of the grounding portion and contacts the ground surface becomes narrow. Therefore, when a large compressive load in the vertical direction is applied to the bottle, stress tends to concentrate on the contact portion, making it difficult to ensure the filling buckling strength. Particularly, in addition to the aforementioned C / B being larger than 0.6 and smaller than 1.2, and the aforementioned A / B being larger than 1.0 and smaller than 3.2, the heel portion and the grounding portion can be surely deformed with little variation over the entire circumferential length.

[0010] In a longitudinal sectional view along the vertical direction, the portion of the bottom surface of the concave portion located in the heel portion extends outward in the radial direction as it goes upward, and呈 a protruding curved shape outward in the radial direction, and may be continuously connected to the outer peripheral surface of the heel portion without a step.

[0011] When viewed in vertical cross section along the vertical direction, the portion of the bottom surface of the recess that is located at the heel portion extends radially outward as it extends upward, and presents a protruding curve that extends radially outward, connecting without any steps to the outer peripheral surface of the heel portion.Therefore, when a large compressive load is applied to the bottle in the vertical direction, stress can be prevented from concentrating at the connection portion between the upper end of the bottom surface of the recess and the outer peripheral surface of the heel portion. [Effects of the Invention]

[0012] According to one aspect of the present invention, the packing buckling strength can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a side view of an embodiment of a bottle. [Figure 2] FIG. 2 is a half-longitudinal cross-sectional view of the bottom of the bottle of FIG. 1. [Figure 3] FIG. 2 is a bottom view of the bottle of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a bottle according to one embodiment of the present invention will be described with reference to the drawings. 1, the bottle 1 according to this embodiment has a mouth 11, a shoulder 12, a body 13, and a bottom 14, which are generally arranged in this order with their central axes aligned on a common axis. The internal volume of the bottle 1 is large enough to hold a content of, for example, 300 ml to 2000 ml.

[0015] Hereinafter, the common axis will be referred to as the bottle axis O, the mouth 11 side along the bottle axis O direction will be referred to as the upper side, and the bottom 14 side will be referred to as the lower side, the direction along the bottle axis O will be referred to as the up-down direction, the direction that intersects the bottle axis O when viewed from the up-down direction will be referred to as the radial direction, and the direction that circles around the bottle axis O will be referred to as the circumferential direction. The bottle 1 is formed integrally from a synthetic resin material by blow molding a preform formed into a cylindrical shape with a bottom by injection molding. A cap (not shown) is attached to the mouth 11. The mouth 11, shoulder 12, body 13, and bottom 14 each have a circular cross-sectional shape perpendicular to the bottle axis O.

[0016] The body 13 has a plurality of rectangular panel portions 13a that are elongated in the vertical direction and spaced apart in the circumferential direction. An annular groove 15 that extends continuously around the entire circumference is formed in the lower end of the body 13, located below the panel portions 13a. The annular groove 15 is formed in a concave curved surface that is recessed radially inward. The annular groove 15 may be formed in a portion of the body 13 other than the lower end. The outer diameter of the lower end of the body 13 is, for example, 55 mm or more and 110 mm or less. In the illustrated example, the outer diameter of the lower end of the body 13 is approximately 82 mm.

[0017] As shown in Figure 2, the bottom 14 includes a bottom wall portion 19 on whose outer peripheral edge the ground contact portion 18 is located, and a cylindrical heel portion 17 that extends radially outward as it moves upward from the outer peripheral edge 18b of the ground contact portion 18 and is formed into a curved surface that protrudes radially outward.

[0018] The ground contact portion 18 has a width in the radial direction and extends continuously around the entire circumference. The upper opening edge of heel portion 17 is connected to the lower opening edge of body portion 13. The upper end of heel portion 17 is continuously connected to the lower opening peripheral edge 15a of the pair of upper and lower opening peripheral edges of annular groove 15 in body portion 13 without any step in the vertical direction. The lower opening edge of heel portion 17 is connected to the outer peripheral edge of bottom wall portion 19, i.e., the outer peripheral edge 18b of ground contact portion 18. The lower end of heel portion 17 is formed into a curved surface that protrudes obliquely downward and faces radially outward. The portion of bottom wall portion 19 that is located radially inward from ground contact portion 18 forms a recessed portion 16 that is recessed upward.

[0019] In this embodiment, a plurality of recesses 21 are provided at equal intervals in the circumferential direction on the bottom portion 14. The recesses 21 extend from a portion of the grounding portion 18 that is radially outward from the inner peripheral edge 18a of the grounding portion 18 across the outer peripheral edge 18b of the grounding portion 18 to the lower end portion of the heel portion 17.

[0020] The upper end portion of the recess 21 is located below the upper end portion of the heel portion 17. As shown in FIG. 3, the bottom surface 22 of the recess 21 has a rectangular shape extending in the radial direction when viewed from below. That is, of the four sides defining the rectangular shape of the bottom surface 22 of the recess 21 when viewed from below, two sides are located at both circumferential ends and extend in the radial direction, and the remaining two sides are located at both radial ends and extend in the circumferential direction. The bottom surface 22 of the recess 21 has a rectangular shape that is long in the radial direction when viewed from below. Note that the bottom surface 22 of the recess 21 may have a square shape extending in the radial direction when viewed from below, or may have a rectangular shape that is long in the circumferential direction.

[0021] When the circumferential interval between the upper end portions located in the heel portion 17 of the bottom surfaces 22 of the recesses 21 adjacent to each other in the circumferential direction is A, and the circumferential size of the upper end portion of the bottom surface 22 of the recess 21 is B, 1.0 < A / B < 3.2, preferably 2.0 < A / B < 3.0 is satisfied. The aforementioned interval A is 3.0 mm or more and 9.0 mm or less, preferably 4.0 mm or more and 8.0 mm or less. The aforementioned size B is 2.0 mm or more and 6.0 mm or less, preferably 2.5 mm or more and 4.0 mm or less.

[0022] The circumferential size of the recess 21 becomes narrower or wider from the heel portion 17 side toward the grounding portion 18 side, and when the circumferential size of the upper end portion of the bottom surface 22 of the recess 21 is B, and the circumferential size of the lower end portion of the bottom surface 22 of the recess 21 located in the grounding portion 18 is C, 0.6 < C / B < 1.2, preferably 0.8 < C / B < 1.0 is satisfied. The aforementioned size C is 1.6 mm or more and 4.8 mm or less, preferably 2.0 mm or more and 3.2 mm or less. In the illustrated example, the circumferential size of the recess 21 narrows from the heel portion 17 side toward the ground contact portion 18 side. The lower end of the recess 21 is located in the radial center of the ground contact portion 18. The aforementioned size C is that of the portion of the bottom surface 22 of the recess 21 that is located in the radial center of the ground contact portion 18.

[0023] 2, in a vertical cross-sectional view along the up-down direction, the portion of bottom surface 22 of recess 21 located at heel portion 17 extends radially outward as it extends upward, presents a protruding curved shape toward the radially outward direction, and is connected without any steps to the outer peripheral surface of heel portion 17. The portion of bottom surface 22 of recess 21 located at heel portion 17 is formed in a protruding curved shape that faces diagonally downward toward the radially outward direction. In a vertical cross-sectional view along the vertical direction, the radius of curvature (approximately 6 mm) of the outer peripheral surface of the lower end of heel portion 17 is smaller than the radius of curvature (approximately 8 mm) of the portion of bottom surface 22 of recess 21 located at heel portion 17. The radially inner end of the bottom surface 22 of the recess 21 at the portion located at the ground contact portion 18 is continuous with the lower surface of the ground contact portion 18 without any step.

[0024] The number of recesses 21 provided is 20 or more, preferably 24 to 32. The plurality of recesses 21 are formed to have the same shape and the same size. Note that, among the plurality of recesses 21, the shape and size of some of the recesses 21 may be different from the shape and size of the other recesses 21.

[0025] As described above, in the bottle 1 according to this embodiment, the bottom 14 is provided with a plurality of equally spaced recesses 21 in the circumferential direction, extending from a portion of the contact portion 18 radially outward from the inner peripheral edge 18a of the contact portion 18 across the outer peripheral edge 18b of the contact portion 18 to the lower end of the heel portion 17. This allows the heel portion 17 and the contact portion 18 to deform with little variation over their entire circumferential length, even if the bottom 14 deforms so that the lower end of the heel portion 17 is pulled radially inward between the contact portion and the contact surface when a large vertical compressive load is applied to the bottle 1. This makes it difficult for the portion of the bottom wall 19 located radially inward of the contact portion 18 to bend, for example, in the radial direction. This, combined with an increase in the bottle internal pressure, reliably improves the buckling strength upon filling.

[0026] Since the aforementioned A / B is greater than 1.0 and smaller than 3.2, the packing buckling strength can be reliably improved. Since the aforementioned C / B is greater than 0.6 and smaller than 1.2, the packing buckling strength can be reliably improved. In particular, since the aforementioned C / B is greater than 0.6 and less than 1.2, and the aforementioned A / B is greater than 1.0 and less than 3.2, the heel portion 17 and the ground contact portion 18 can be reliably deformed with little variation over their entire circumferential length.

[0027] When viewed in vertical cross section along the vertical direction, the portion of the bottom surface 22 of the recess 21 located at the heel portion 17 extends radially outward as it extends upward, and presents a protruding curve extending radially outward, connecting without any steps to the outer peripheral surface of the heel portion 17.Therefore, when a large compressive load is applied to the bottle 1 in the vertical direction, stress concentration at the connection portion between the upper end of the bottom surface 22 of the recess 21 and the outer peripheral surface of the heel portion 17 can be suppressed.

[0028] Next, a verification test of the above-described effects will be described.

[0029] Several types of bottles with different A / B ratios were modeled, and the stresses generated in each part of each bottle when a compressive load was applied in the vertical direction were numerically analyzed.The vertical compressive load that would cause a fold extending radially, for example, in the part of the bottom wall located radially inward from the ground contact part was calculated. As a result, it was confirmed that in the bottle of Comparative Example 1, in which the aforementioned A / B was 1.0 or less, the aforementioned fold occurred starting from the part of the ground contact portion that was located between adjacent recesses in the circumferential direction and abutted against the ground contact surface. In the bottle of Comparative Example 2, in which the above-mentioned A / B was 3.2 or more, it was confirmed that the above-mentioned crease occurred starting from the part of the ground contact portion where the recessed portion was located. Furthermore, it was confirmed that in Bottle 1, in which the aforementioned A / B ratio was greater than 1.0 and less than 3.2, the aforementioned breakage did not occur even when the vertical compressive load that caused the aforementioned breakage in the bottles of Comparative Examples 1 and 2 was applied.

[0030] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0031] For example, the size of the recess 21 in the circumferential direction may be the same over the entire length. The bottom surface 22 of the recess 21 may extend linearly outward in the radial direction as it extends upward.

[0032] The synthetic resin material forming the bottle 1 may be, for example, polyethylene terephthalate, polyethylene naphthalate, amorphous polyester, or a blend of these materials, and may be changed as appropriate. The bottle 1 is not limited to a single-layer structure, but may be a laminated structure having an intermediate layer, such as a layer made of a resin material with gas barrier properties, a layer made of recycled material, or a layer made of a resin material with oxygen absorbing properties.

[0033] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and the above-described variations may be combined as appropriate. [Explanation of symbols]

[0034] 1 bottle 14 Bottom 17 Heel 18 Grounding part 18a Inner edge of the contact area 18b Outer edge of the ground contact area 19 Bottom wall 21 Recess 22 Bottom of recess

Claims

1. A cylindrical bottle with a bottom made of a synthetic resin material, The bottom portion comprises a bottom wall portion having a ground contact portion located on an outer peripheral edge thereof, and a cylindrical heel portion extending radially outward as it moves upward from the outer peripheral edge of the ground contact portion and formed with a curved surface protruding radially outward, The bottom portion has a plurality of recesses that are equally spaced apart in the circumferential direction, the recesses extending from a portion of the ground contact portion that is radially outwardly spaced from the inner peripheral edge of the ground contact portion across the outer peripheral edge of the ground contact portion to a lower end of the heel portion, The bottom surface of the recess has a rectangular shape extending in the radial direction when viewed from below, A bottle in which, when the circumferential distance between the upper ends of the bottom surfaces of the recesses that are adjacent to each other in the circumferential direction and that are located in the heel portion is A and the circumferential size of the upper ends of the bottom surfaces of the recesses in the circumferential direction is B, the relationship 1.0 < A / B < 3.2 is satisfied.

2. The size of the recess in the circumferential direction becomes narrower or wider as it goes from the heel portion side to the ground contact portion side, 2. The bottle of claim 1, wherein the circumferential size of the upper end of the bottom surface of the recess is B and the circumferential size of the lower end of the bottom surface of the recess that is located in the ground contact portion is C, and the relationship C / B satisfies 0.6<C / B<1.

2.

3. 3. The bottle according to claim 1, wherein, in a vertical cross-sectional view along the vertical direction, a portion of the bottom surface of the recess located at the heel portion extends radially outward as it extends upward, exhibits a protruding curved shape extending radially outward, and is connected without steps to the outer peripheral surface of the heel portion.

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