JP7300922B2 - pressure bottle - Google Patents

Description

The present invention relates to a pressure-resistant bottle.

Conventionally, as shown in Patent Document 1 below, for example, a mouth portion, a shoulder portion, a body portion, and a bottom portion are continuously arranged in this order from top to bottom along the axial direction of the bottle, and are made of a synthetic resin material. The bottom portion includes a central wall portion positioned on the bottle axis and a connecting peripheral wall portion connecting the outer peripheral edge of the central wall portion and the body portion, and the connecting peripheral wall portion is spaced in the circumferential direction Three or more vertical grooves are formed with a gap between them, and legs protruding downward from the central wall are formed in each portion located between the circumferentially adjacent vertical grooves in the connecting peripheral wall. pressure-resistant bottles are known.

JP-A-7-164514

However, in the conventional pressure-resistant bottle, there is a recent demand for weight reduction and strong carbonation of the content liquid to be filled. rice field.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pressure-resistant bottle that is capable of suppressing downward bulging deformation of the central wall when the internal pressure rises. do.

The present invention employs the following means to solve the above problems. That is, the pressure-resistant bottle of the present invention has a mouth portion, a shoulder portion, a body portion, and a bottom portion which are continuously arranged in this order from top to bottom along the axial direction of the bottle and are integrally formed of a synthetic resin material. The bottom portion includes a central wall portion positioned on the bottle axis, and a connecting peripheral wall portion connecting the outer peripheral edge of the central wall portion and the body portion, and the connecting peripheral wall portion is spaced apart in the circumferential direction. Three or more vertical grooves are formed with an opening therebetween, and leg portions protruding downward from the central wall in each portion located between the circumferentially adjacent vertical grooves in the connecting peripheral wall. is formed, and a grounding portion extending in the circumferential direction is formed at the lower end portion of the leg portion, wherein the groove bottom surface facing radially outward of the inner surface defining the vertical groove portion is downward an upper portion that extends radially inward and downward from the body portion, and a lower portion that extends downward from the upper portion and is connected to the outer peripheral edge of the central wall portion. The upper portion extends linearly inward in the radial direction as it goes downward over the entire area except for the upper end portion, and the lower portion is formed in a curved surface protruding outward in the radial direction. In a vertical cross-sectional view along the axis, the length of the lower portion along the outer surface of the pressure-resistant bottle is longer than the length of the upper portion along the outer surface of the pressure-resistant bottle , and the central wall portion is The leg portion is formed in a circular shape and is flat or formed in a curved surface that protrudes downward, and the leg portion extends upward as it goes radially inward from the ground portion, An inner wall portion connected to the outer peripheral edge is provided, and a connecting portion between the inner wall portion and the central wall portion is positioned radially outside a connecting portion between the lower portion and the central wall portion.

According to the present invention, the upper portion of the groove bottom surface extends linearly inward in the radial direction as it goes downward over the entire area except for the upper end portion. It becomes easier to deform toward the outer side of the direction, suppressing the increase of the internal pressure and relaxing the stress generated in the central wall portion. As a result, when the internal pressure rises, the central wall portion can be prevented from being bulged and deformed downward.
The lower part of the groove bottom surface is formed in a curved surface that protrudes outward in the radial direction. Since the length is greater than the length of the upper part of the groove bottom surface along the groove, it is possible to secure a large area in the bottom part. Together with the outward deformation in the radial direction, the stress generated in the central wall portion can be reliably suppressed.

In the vertical cross-sectional view, the length of the upper part along the outer surface of the pressure bottle is the central wall part where the bottle axis is located along the outer surface of the pressure bottle from the upper edge of the upper part through the lower part. 30% or more and 40% or less of the length up to the center.

In this case, in the longitudinal cross-sectional view, the length of the upper portion of the groove bottom surface along the outer surface of the pressure bottle extends along the outer surface of the pressure bottle from the upper edge of the upper portion of the groove bottom surface through the lower portion of the groove bottom surface to the central wall Since it is 30% or more and 40% or less of the length to the center of the groove, when the internal pressure rises, the upper portion of the groove bottom surface is radially outward while suppressing the load applied to the lower portion of the groove bottom surface from above. can be reliably transformed in the direction of

The central wall portion may be formed in a flat disc shape.

In this case, since the central wall portion is formed in a flat disc shape, the central wall portion is directed downward when the internal pressure increases, compared with the case where the central wall portion is formed in a curved surface shape that protrudes downward. It is possible to make it difficult to bulge and deform.

In the vertical cross-sectional view, the length of the upper portion along the outer surface of the pressure-resistant bottle may be longer than the radial distance between the connecting portion between the lower portion and the central wall portion and the bottle axis.

In this case, in the vertical cross-sectional view, the length of the upper portion of the groove bottom along the outer surface of the pressure-resistant bottle is longer than the radial distance between the connecting portion between the lower portion and the central wall portion and the bottle axis. Therefore, the upper portion of the bottom surface of the groove can be smoothly deformed radially outward when the internal pressure increases while securing the bending rigidity of the central wall portion in the axial direction of the bottle.

The leg portion includes an inner wall portion that extends upward as it goes radially inward from the ground portion and is connected to the outer peripheral edge of the central wall portion, and the inner wall portion and the central wall portion are connected. The portion may be located radially outside the connecting portion between the lower portion and the central wall portion.

In this case, since the radial positions of the connecting portion between the inner wall portion and the central wall portion and the connecting portion between the lower portion of the groove bottom surface and the central wall portion are different from each other, the radial positions of these connecting portions Compared to the case where the grooves are the same, when the internal pressure rises, a stepped portion extending in the circumferential direction is less likely to occur at each connection portion between the inner wall portion and the lower portion of the groove bottom surface and the central wall portion, and cracks can be suppressed.
Since the connecting portion between the inner wall portion and the central wall portion is located radially outside the connecting portion between the lower portion of the groove bottom surface and the central wall portion, the former connecting portion is Compared to when they are positioned at the same radial position and when they are positioned radially inward, it is possible to make the rising angle of the inner wall part with respect to the contact part steeper, and when the internal pressure rises, The inner wall portion is less likely to collapse downward around the ground contact portion, and ground contact stability can be provided.

A portion of the upper portion located below the upper end portion may have an inclination angle of 10° or more and 30° or less with respect to the axial direction of the bottle.

In this case, of the upper portion of the groove bottom surface, the portion located below the upper end portion has an inclination angle of 10° or more and 30° or less with respect to the axial direction of the bottle. It is possible to prevent the central wall portion from being deformed to bulge downward during the ascent.
If the inclination angle is less than 10°, the upper portion of the bottom surface of the groove becomes less likely to deform radially outward when the internal pressure increases, and it may become difficult to relax the stress generated in the central wall portion. If the inclination angle exceeds 30°, the distance in the radial direction between the contact portion and the bottle shaft is shortened, which may impede contact stability.

According to the present invention, it is possible to prevent the central wall portion from being deformed to bulge downward when the internal pressure increases.

1 is a side view of a pressure-resistant bottle shown as an embodiment of the present invention, viewed from the outside in the radial direction; FIG. FIG. 2 is a vertical cross-sectional view showing a main portion of the bottom portion of the pressure-resistant bottle shown in FIG. 1;

An embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the pressure-resistant bottle 1 according to the present embodiment has a mouth portion 11, a shoulder portion 12, a body portion 13, and a bottom portion 14 arranged in this order from top to bottom along the direction of the bottle axis O. They are connected and integrally formed of a synthetic resin material. The pressure-resistant bottle 1 is formed by, for example, biaxial stretch blow molding. The pressure-resistant bottle 1 is filled with, for example, a carbonated beverage or the like that increases the internal pressure in a sealed state.

The mouth portion 11, the shoulder portion 12, the body portion 13 and the bottom portion 14 are each formed in a cylindrical shape and arranged coaxially with the bottle axis O. As shown in FIG.
Hereinafter, when viewed from the direction of the bottle axis O, the direction intersecting with the bottle axis O is called the radial direction, and the direction rotating around the bottle axis O is called the circumferential direction.

The outer surface of the mouth portion 11 is formed with a male screw portion to which a cap (not shown) is detachably screwed. A neck ring 26 extending continuously over the entire length in the circumferential direction is provided on the outer surface of the mouth portion 11 at a portion located below the male threaded portion. A pressure-resistant bottle that does not have the neck ring 26 may be used.

The shoulder portion 12 has a larger diameter from the upper side to the lower side. The lower end portion of the shoulder portion 12 smoothly continues to the upper end portion of the body portion 13 without steps.
The upper end portion of the body portion 13 includes an upper straight cylindrical portion 13a extending straight downward from the lower end portion of the shoulder portion 12, and an upper reduced diameter portion extending radially inward as it goes downward from the lower end portion of the upper straight cylindrical portion 13a. 13b and.

The bottom portion 14 includes a central wall portion 15 positioned on the bottle axis O, and a connecting peripheral wall portion 16 connecting the outer peripheral edge of the central wall portion 15 and the lower end portion of the body portion 13 . The upper end portion of the connecting peripheral wall portion 16 smoothly continues to the lower end portion of the body portion 13 without a step.
The lower end portion of the body portion 13 includes a lower straight cylindrical portion 13c that extends straight upward from the upper end portion of the connecting peripheral wall portion 16, and a lower straight cylindrical portion 13c that extends inward in the radial direction as it goes upward from the upper end portion of the lower straight cylindrical portion 13c. a portion 13d;

The upper straight tube portion 13a and the lower straight tube portion 13c are portions of the pressure bottle 1 having the largest outer diameter. Each outer diameter of the upper straight tube portion 13a and the lower straight tube portion 13c is, for example, 62.2 mm or more and 70.5 mm or less, and is approximately 66 mm in the illustrated example.
The length of the pressure-resistant bottle 1 in the bottle axis O direction is, for example, 198 mm or more and 220 mm or less, and is approximately 206 mm in the illustrated example. The content of the pressure-resistant bottle 1 is, for example, 400 ml or more and 600 ml or less, and in the illustrated example, the pressure-resistant bottle 1 is for 500 ml.
Note that each of the above numerical values may be changed as appropriate.

The central wall portion 15 is formed in a disc shape coaxial with the bottle axis O. As shown in FIG. The central wall portion 15 is formed flat. Note that the central wall portion 15 may be formed in a curved surface that protrudes downward.
Three or more vertical groove portions 17 are formed in the connecting peripheral wall portion 16 at intervals in the circumferential direction. Leg portions 18 protruding downward from the central wall portion 15 are formed in portions of the connecting peripheral wall portion 16 located between the longitudinal groove portions 17 adjacent in the circumferential direction. An odd number of the longitudinal grooves 17 and the leg portions 18 are formed on the connecting peripheral wall portion 16, and in the illustrated example, five of each are formed. The plurality of longitudinal grooves 17 are formed with the same shape and size, and are arranged at equal intervals in the circumferential direction. The plurality of leg portions 18 are formed with the same shape and size, and are arranged at equal intervals in the circumferential direction. The bottom portion 14 is formed in a so-called petaloid shape.
An even number of each of the vertical groove portions 17 and the leg portions 18 may be formed on the connecting peripheral wall portion 16 .

The leg portion 18 includes a ground contact portion 22, an outer wall portion 20 extending upward from the ground contact portion 22 and connected to the lower end portion of the trunk portion 13, an outer wall portion 20 extending radially inward from the contact portion 22, and a center wall. and an inner wall portion 19 connected to the outer peripheral edge of the portion 15 .

The ground portion 22 is formed at the lower end portion of the leg portion 18 . The grounding portions 22 are intermittently arranged over the entire length in the circumferential direction and extend along the same circle centered on the bottle axis O in a bottom view of the bottom portion 14 from below. The ground portion 22 is positioned below the central wall portion 15 . The ground portion 22 is spaced downward from the central wall portion 15 by, for example, 4 mm or more and 6 mm or less, and in the illustrated example, is spaced about 5 mm. Note that this numerical value may be changed as appropriate. Further, the grounding portion 22 may be formed in a linear shape with a very small radial size, or may be formed in a planar shape with a radial size.

The front and back surfaces of the outer wall portion 20 are oriented in the radial direction. The outer wall portion 20 extends radially inward from the upper side to the lower side. As shown in FIG. 2 , in the outer wall portion 20, a lower end portion (hereinafter referred to as an outer connecting portion) 20a that is connected to the grounding portion 22 from the outside in the radial direction has a radial It is curved so as to form a curved shape that protrudes toward the outside. The radius of curvature of the outer connecting portion 20a in the vertical cross-sectional view is, for example, 12 mm or more and 25 mm or less, and is about 18 mm in the illustrated example. Note that this numerical value may be changed as appropriate.

A portion (hereinafter referred to as an upper portion) 20b of the outer wall portion 20 located above the outer connecting portion 20a is formed in a curved surface shape that protrudes outward in the radial direction. The radius of curvature of the upper portion 20b in the vertical cross section is larger than the radius of curvature of the outer connecting portion 20a, for example, 86 mm or more and 207 mm or less, and in the illustrated example, it is about 150 mm. Note that this numerical value may be changed as appropriate. The upper portion 20b is smoothly connected to the lower end of the trunk portion 13 and the upper end of the outer connecting portion 20a without steps.

The front and back surfaces of the inner wall portion 19 face the direction of the bottle axis O, respectively. The inner wall portion 19 extends upward as it extends radially inward from the ground contact portion 22 . A radially inner end portion of the inner wall portion 19 connected to the central wall portion 15 smoothly continues to the central wall portion 15 without a step.
A portion (hereinafter referred to as an inner connecting portion) 19a of the inner wall portion 19, which is connected to the grounding portion 22 from the inner side in the radial direction, has a curved shape that protrudes downward in a vertical cross-sectional view along the direction of the bottle axis O. It is curved like an eggplant. In the vertical cross-sectional view, the radius of curvature of the inner connecting portion 19a is, for example, 7 mm or more and 12 mm or less, and is about 9 mm in the illustrated example. Note that this numerical value may be changed as appropriate.

A portion (hereinafter referred to as an inner portion) 19b of the inner wall portion 19 positioned radially inward of the inner connecting portion 19a is curved in a curved shape projecting upward in the vertical cross-sectional view. are doing. That is, in the vertical cross-sectional view, the direction in which the inner connecting portion 19a protrudes and the direction in which the inner portion 19b protrudes are opposite to each other. In the vertical cross-sectional view, the length of the inner portion 19b along the outer surface of the pressure bottle 1 is longer than the length of the inner connecting portion 19a along the outer surface of the pressure bottle 1, and the radius of curvature of the inner portion 19b is equal to the length of the inner connecting portion It is larger than the radius of curvature of 19a.

Here, the bottom portion 14 includes a pair of side wall portions 21 (see FIG. 1) integrally connecting both ends in the circumferential direction of the ground portion 22, the inner wall portion 19 and the outer wall portion 20, respectively. The front and back surfaces of the side wall portion 21 face the circumferential direction.
The vertical groove portion 17 is defined by a groove bottom surface 23 facing radially outward and surfaces of side wall portions 21 that protrude radially outward from both circumferential ends of the groove bottom surface 23 and face each other in the circumferential direction. is made.

As shown in FIG. 2, the groove bottom surface 23 extends radially inward as it goes downward. The groove bottom surface 23 includes an upper portion 31 extending downward from the body portion 13 and a lower portion 32 extending downward from the upper portion 31 and connected to the outer peripheral edge of the central wall portion 15 .

The upper portion 31 linearly extends radially inward as it goes downward over the entire area except for the upper end portion 31a. A portion of the upper portion 31 located below the upper end portion 31a is hereinafter referred to as a straight portion 31b.
The upper end portion 31a is formed into a curved surface that protrudes outward in the radial direction. In the vertical cross-sectional view, the radius of curvature of the upper end portion 31a is, for example, approximately 10 mm. In the vertical cross-sectional view, the length of the upper end portion 31a along the outer surface of the pressure-resistant bottle 1 (between symbols A and B) is the length of the upper portion 31 along the outer surface of the pressure-resistant bottle 1 (between symbols A and C), for example It is less than 10%. The upper end portion 31a smoothly connects to the lower end portion of the body portion 13 without a step.
The inclination angle θ of the linear portion 31b with respect to the direction of the bottle axis O is, for example, 10° or more and 30° or less, and is approximately 22° in the illustrated example. Note that this numerical value may be changed as appropriate.

In the vertical cross-sectional view, the length of the upper portion 31 along the outer surface of the pressure-resistant bottle 1 is longer than the radial distance between the connecting portion F between the lower portion 32 and the central wall portion 15 and the bottle axis O. In the illustrated example, the length of the straight portion 31b along the outer surface of the pressure-resistant bottle 1 is also longer than the radial distance between the connecting portion F and the bottle axis O. As shown in FIG. The length of the linear portion 31b along the outer surface of the pressure-resistant bottle 1 may be less than or equal to the radial distance between the connecting portion F and the bottle axis O.

In the vertical cross-sectional view, the length of the upper portion 31 along the outer surface of the pressure-resistant bottle 1 extends along the outer surface of the pressure-resistant bottle 1 from the upper edge A of the upper portion 31 through the lower portion 32 to the central wall where the bottle axis O is located. For example, it is 30% or more and 40% or less of the length up to the center of the portion 15, and is about 34% in the illustrated example. Note that this numerical value may be changed as appropriate.
The radial distance between the connection portion F between the lower portion 32 and the central wall portion 15 and the bottle axis O is along the outer surface of the pressure-resistant bottle 1 from the upper edge A of the upper portion 31 through the lower portion 32 to the central wall. For example, it is 15% or more and 25% or less of the length up to the center of the portion 15, and is about 21% in the illustrated example. Note that this numerical value may be changed as appropriate.

The lower portion 32 is formed in a curved surface that protrudes outward in the radial direction. The lower portion 32 smoothly connects to the lower edge of the upper portion 31 and the outer peripheral edge of the central wall portion 15 without steps. The lower portion 32 is formed by connecting a plurality of circular arc portions having mutually different curvature radii in the vertical cross-sectional view. In the illustrated example, the curvature radius of a lower end portion 32a of the lower portion 32 is smaller than the curvature radius of a portion (hereinafter referred to as a main portion) 32b located above the lower end portion 32a in the vertical cross-sectional view. In the vertical cross-sectional view, the length of the lower end portion 32a of the lower portion 32 along the outer surface of the pressure-resistant bottle 1 (between symbols D and F) is the length of the main portion 32b of the lower portion 32 along the outer surface of the pressure-resistant bottle 1 (symbol C ~ D) is shorter. When viewed in longitudinal section, the radius of curvature of the lower end portion 32a of the lower portion 32 is, for example, approximately 16 mm, and the radius of curvature of the main portion 32b of the lower portion 32 is, for example, approximately 21 mm.

In the vertical cross-sectional view, the length of the lower portion 32 along the outer surface of the pressure-resistant bottle 1 (between symbols C and F) is longer than the length of the upper portion 31 along the outer surface of the pressure-resistant bottle 1 . The length of the lower portion 32 along the outer surface of the pressure-resistant bottle 1 is from the upper edge A of the upper portion 31 to the center of the central wall portion 15 via the lower portion 32 along the outer surface of the pressure-resistant bottle 1 in the vertical cross-sectional view. For example, it is 40% or more and 50% or less of the length of , and in the illustrated example, it is about 45%. Note that this numerical value may be changed as appropriate. The length of the lower portion 32 along the outer surface of the pressure bottle 1 may be shorter than the length of the upper portion 31 along the outer surface of the pressure bottle 1 .

A connecting portion E between the inner wall portion 19 of the leg portion 18 and the central wall portion 15 is located radially outside a connecting portion F between the lower portion 32 of the groove bottom surface 23 and the central wall portion 15 . The former connecting portion E is located radially inside the lower edge of the main portion 32b. The radial distance between the former connecting portion E and the latter connecting portion F is smaller than the radial distance between the former connecting portion E and the lower edge of the main portion 32b. The radial distance between the former connection portion E and the latter connection portion F may be equal to or greater than the radial distance between the former connection portion E and the lower edge of the main portion 32b.

As described above, according to the pressure-resistant bottle 1 according to the present embodiment, the upper portion 31 of the groove bottom surface 23 extends linearly inward in the radial direction as it goes downward over the entire area except the upper end portion 31a. Therefore, when the internal pressure rises, the upper portion 31 of the groove bottom surface 23 is easily deformed radially outward, suppressing the rise of the internal pressure and relaxing the stress generated in the central wall portion 15 . As a result, it is possible to prevent the central wall portion 15 from being deformed to bulge downward when the internal pressure increases.

A lower portion 32 of the groove bottom surface 23 is formed in a curved surface protruding outward in the radial direction, and the length of the lower portion 32 along the outer surface of the pressure-resistant bottle 1 is along the outer surface of the pressure-resistant bottle 1 in the vertical cross-sectional view. Since the length of the upper portion 31 of the groove bottom surface 23 is greater than or equal to the length of the upper portion 31, it is possible to secure a large area in the bottom portion 14. When the internal pressure rises, the lower portion 32 of the groove bottom surface 23, which is connected to the central wall portion 15, can be expanded. Instead, the upper portion 31 is deformed radially outward, so that the stress generated in the central wall portion 15 can be reliably suppressed.

In the vertical cross-sectional view, the length of the upper portion 31 along the outer surface of the pressure-resistant bottle 1 extends from the upper edge A of the upper portion 31 to the center of the central wall portion 15 via the lower portion 32 along the outer surface of the pressure-resistant bottle 1. Since it is 30% or more and 40% or less of the length to the upper part 31, when the internal pressure rises, the upper part 31 can be reliably deformed radially outward while suppressing the load applied to the lower part 32 from the upper part 31. can be done.

Since the central wall portion 15 is formed in the shape of a flat disk, the central wall portion 15 is directed downward when the internal pressure is increased, compared with the case where the central wall portion 15 is formed in a curved surface that protrudes downward. It is possible to make it difficult to bulge and deform.

In the vertical cross-sectional view, the length of the upper portion 31 along the outer surface of the pressure-resistant bottle 1 is longer than the radial distance between the connecting portion F between the lower portion 32 and the central wall portion 15 and the bottle axis O. , while ensuring the bending rigidity of the central wall portion 15 in the direction of the bottle axis O, the upper portion 31 can be smoothly deformed radially outward when the internal pressure is increased.

Since the radial positions of the connection portion E between the inner wall portion 19 and the central wall portion 15 and the connection portion F between the lower portion 32 and the central wall portion 15 are different from each other, the diameters of these connection portions E and F are different. Compared to the case where the directional positions are the same, when the internal pressure rises, the connecting portions E and F between the inner wall portion 19 and the lower portion 32 and the central wall portion 15 have stepped portions extending in the circumferential direction. It becomes difficult to develop, and the occurrence of cracks can be suppressed.

Since the connecting portion E between the inner wall portion 19 and the central wall portion 15 is located radially outside the connecting portion F between the lower portion 32 and the central wall portion 15, the former connecting portion E is the latter connecting portion. It is possible to make the rising angle of the inner wall portion 19 with respect to the grounding portion 22 steeper than when it is positioned at the same radial position with respect to F and when it is positioned radially inward. As a result, when the internal pressure rises, the inner wall portion 19 is less likely to fall downward around the ground contact portion 22, and ground contact stability can be achieved.

Since the inclination angle θ of the linear portion 31b of the groove bottom surface 23 with respect to the direction of the bottle axis O is 10° or more and 30° or less, the central wall portion 15 is downwardly moved when the internal pressure is increased without hindering the grounding stability. It is possible to suppress swelling deformation toward.
If the inclination angle θ is less than 10°, the upper portion 31 is less likely to deform radially outward when the internal pressure increases, and the stress generated in the central wall portion 15 may be less likely to be relieved. If the inclination angle θ exceeds 30°, the distance in the radial direction between the ground contact portion 22 and the bottle axis O is shortened, which may impede ground contact stability.

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

For example, in the above-described embodiment, as the lower portion 32 of the groove bottom surface 23, a plurality of arcuate portions having different radii of curvature from each other in the vertical cross section are connected, but a configuration consisting of only one arcuate portion is adopted. may
In the vertical cross-sectional view, the length of the upper portion 31 of the groove bottom surface 23 along the outer surface of the pressure-resistant bottle 1 is the radial direction of the connecting portion F between the lower portion 32 of the groove bottom surface 23 and the central wall portion 15 and the bottle axis O. may be less than or equal to the distance of
The connecting portion E between the inner wall portion 19 of the leg portion 18 and the central wall portion 15 may be positioned at the same radial position as the connecting portion F between the lower portion 32 and the central wall portion 15. may be located inside the

Moreover, the synthetic resin material forming the pressure-resistant bottle 1 may be appropriately changed, for example, polyethylene terephthalate, polyethylene naphthalate, amorphous polyester, or a blend material thereof.
Furthermore, the pressure-resistant bottle 1 is not limited to a single-layer structure, and may be a laminated structure having an intermediate layer. Examples of the intermediate layer include a layer made of a resin material having gas barrier properties, a layer made of a recycled material, a layer made of a resin material having oxygen absorption properties, a combination of these layers, or a deposited layer.

In addition, it is possible to appropriately replace the constituent elements in the above-described embodiment with well-known constituent elements without departing from the scope of the present invention, and the above modifications may be combined as appropriate.

1 pressure-resistant bottle 11 mouth portion 12 shoulder portion 13 body portion 14 bottom portion 15 central wall portion 16 connecting peripheral wall portion 17 longitudinal groove portion 18 leg portion 19 inner wall portion 22 grounding portion 23 groove bottom surface 31 upper portion 31a upper end portion 31b straight portion (of the upper portion, part located below the upper end)
32 lower part A upper edge of the upper part E connecting part between the inner wall part and the central wall part F connecting part between the lower part and the central wall part O bottle axis θ inclination angle

Claims (5)

The mouth portion, the shoulder portion, the body portion, and the bottom portion are connected in this order from top to bottom along the axial direction of the bottle, and are integrally formed of a synthetic resin material,
The bottom portion includes a central wall portion positioned on the bottle axis, and a connecting peripheral wall portion connecting the outer peripheral edge of the central wall portion and the body portion,
Three or more vertical grooves are formed in the connecting peripheral wall at intervals in the circumferential direction,
A leg portion projecting downward from the central wall portion is formed in each portion of the connecting peripheral wall portion located between the longitudinal groove portions adjacent in the circumferential direction,
A pressure-resistant bottle in which a ground portion extending in a circumferential direction is formed at the lower end of the leg,
Of the inner surfaces that define the longitudinal groove portion, a groove bottom surface facing radially outward extends radially inward as it goes downward, and an upper portion that extends downward from the body portion; a lower portion extending downward from and connected to the outer peripheral edge of the central wall portion;
The upper portion extends linearly inward in the radial direction as it goes downward over the entire area except for the upper end,
The lower portion is formed in a curved surface protruding outward in the radial direction,
In a vertical cross-sectional view along the bottle axis, the length of the lower portion along the outer surface of the pressure-resistant bottle is equal to or greater than the length of the upper portion along the outer surface of the pressure-resistant bottle ,
The central wall portion has a circular shape when viewed from above and below, and is flat or formed in a curved surface protruding downward,
The leg portion includes an inner wall portion that extends upward as it goes radially inward from the ground contact portion and that is connected to the outer peripheral edge of the central wall portion,
A pressure-resistant bottle, wherein a connecting portion between the inner wall portion and the central wall portion is located radially outside a connecting portion between the lower portion and the central wall portion. In the vertical cross-sectional view, the length of the upper part along the outer surface of the pressure bottle is the central wall part where the bottle axis is located along the outer surface of the pressure bottle from the upper edge of the upper part through the lower part. 2. The pressure-resistant bottle according to claim 1, wherein the length to the center of the bottle is 30% or more and 40% or less. 3. The pressure-resistant bottle according to claim 1, wherein said central wall portion is shaped like a flat disk. The length of the upper portion along the outer surface of the pressure-resistant bottle is longer than the radial distance between the connecting portion between the lower portion and the central wall portion and the bottle axis in the vertical cross-sectional view. 4. The pressure-resistant bottle according to any one of 1 to 3. 5. The pressure-resistant bottle according to any one of claims 1 to 4 , wherein the portion of the upper portion located below the upper end portion has an inclination angle of 10° or more and 30° or less with respect to the axial direction of the bottle.

Images