JP4876145B2 - Glass bottle - Google Patents

Description

  The present invention relates to a glass bottle in which a plurality of knurlings (projections) are provided in parallel in the circumferential direction along the outer peripheral edge of the bottle bottom.

A protrusion called a knurling is usually formed on the bottom of the glass bottle. This is mainly to reduce defects (minute cracks) caused by thermal shock when the glass bottle immediately after molding is placed on the conveyor and mechanical shock in the subsequent process. That is, the knurling comes into contact with the conveyor surface, and the contact area is reduced, so that the occurrence of defects is reduced.
There are various shapes of the knurling, but most of them are formed radially in parallel at a predetermined interval on the outer peripheral portion of the bottom surface (radial direction or a direction slightly inclined from the radial direction) (FIGS. 4 and 5).
Such knurling is described in Patent Document 1 below, for example.

In addition, when a glass bottle is filled with a liquid content (beverage, seasoning, etc.) and distributed, the glass bottle may be destroyed due to a water hammer phenomenon. This is because, for example, when a carton filled with a glass bottle is lowered, when the glass bottle is lowered rapidly, the inner solution stays in inertia, so the bottom of the bottle becomes negative pressure and vacuum bubbles are generated. The solution falls abruptly and collides with the bottom, and the bottle is destroyed by the impact.
A bottle shape resistant to the impact of such a water hammer is described in Patent Document 2 below.

JP 2006-264715 A Japanese Patent No. 3644215

The broken line in FIG. 8 is a superposition of the shape of the bottle 5 main body (part other than the knurling) having the radius of curvature R5 of the skirt and the shape of the knurling 51 (both are contour lines in the radial longitudinal section), and the solid line is the curvature of the skirt. The bottle 4 body shape and the knurling 41 shape when the radius is increased to R1.
The knurling 51 is formed in a curved portion having a curvature radius R5 (curvature center O5), and the knurling 41 is formed in a curved portion having a curvature radius R1 (curvature center O1).
In the case of the radius of curvature R5 of the skirt, A5 is the lowest part of the bottle body, B5 is the lowest part of the knurling, and the distance (radius) a from A5 and B5 to the bottle center is the same.
In the case of the curvature radius R1 of the skirt, A4 is the lowest part of the bottle body, B4 is the lowest part of the knurling, and the distance (radius) b from A4 and B4 to the bottle center is equal.
Thus, conventionally, the radial position of the lowermost part of the knurling and the lowermost part of the bottle body has been designed to be equal.
As is apparent from FIG. 8, when the curvature radius of the skirt is increased, the radius (grounding radius) at the lowest position of the knurling is decreased (b <a).

FIG. 5 shows a bottle which is relatively tall with respect to the outer diameter on the left side (a large aspect ratio) and a bottle which is relatively short on the right side. The fall angle is the angle of the bottle axis with respect to the vertical line when the bottle is gradually tilted and starts to fall. If the fall angle is small, the bottle tends to fall.
Tall bottles are easy to fall down, so the radius of curvature of the hem is relatively small so that the ground contact radius is as large as possible and the fall angle is as large as possible.
Take a bottle with an outer diameter of 52 mm and a height of about 151 mm as a tall bottle, and a bottle with an outer diameter of 58 mm and a height of 120 mm as an example of a short bottle.
The tall bottle has a radii of curvature of 5 mm and a fall angle of 17 °.
The short bottle has a radii of curvature of 7 mm and a tipping angle of 21 °.

In general, the strength against the water hammer can be increased by increasing the radius of curvature in the longitudinal section of the bottle bottom surface. When the curvature radius of the skirt is small, fine scratches generated on the inner surface due to the impact of the water hammer can be increased in places where a large stress is generated in the water hammer. Glass bottles are greatly weakened by fine scratches. Furthermore, if the radius of curvature of the skirt is small, the internal stress itself generated by the water hammer also increases, so the bottle becomes very easy to break.
The tall bottle has a small radius of curvature at the skirt, so that when the water hammer phenomenon occurs, many scratches can be generated, and a large internal stress is generated and is easily broken.
If the radius of curvature of the hem of the tall bottle is increased from 5 mm to 6 mm, the glass thickness of the hem or bottom increases by 0.3 mm, the internal stress generated decreases, and the scratches decrease and are difficult to break. Become.
When the maximum generated stress is calculated when the dynamic pressure of the inner solution is 2 MPa due to the water hammer phenomenon, it is 114.4 MPa when the curvature radius of the skirt is 5 mm and 92.1 MPa when the curvature radius of the skirt is 6 mm. If the maximum generated stress is greater than 100 MPa, the risk of water hammer failure is high. Therefore, the risk of water hammer failure is high when the radius of curvature of the skirt is 5 mm, and the risk is low when it is 6 mm.

  However, as shown in FIG. 8, when the radius of curvature of the skirt is increased, the radius b at the lowest position of the knurling is reduced, so that the fall angle is reduced from 17 ° to 15.5 °, and the production line or filling is performed. There is a problem that bottles fall on the line and are not practical.

  Therefore, the present inventors have devised that the lowest part of the knurling is positioned radially outward from the lowest part of the bottom of the bottle body (the part where the knurling is not formed).

  Since the bottom part of the knurling is outside the bottom part of the bottle body, even if the radius of curvature of the hem is increased and the bottom part of the bottle body moves inward, the bottom part of the knurling remains the same as before, Can be reduced.

FIG. 6 shows an example of the glass bottle 3 in which the lowermost part of the knurling is positioned radially outward from the lowermost part of the bottle body.
In FIG. 6, a solid line indicates a main body shape (curvature radius R <b> 1) and a knurling outline (radial cross section) in the vicinity of the bottom of the glass bottle 3. The thick broken line indicates the main body shape (curvature radius R5) of the conventional glass bottle 5.
The conventional glass bottle 5 is a round bottle having an outer diameter of 52 mm and a height of about 151 mm, and the curvature radius R5 of the skirt is 5 mm. The lowermost part A5 of the bottle body (the part other than the knurling) and the lowermost part B5 (FIG. 8) of the knurling 51 are both located directly below the center O5 of the arc curve of the hem, which is a = 20.85 mm outside. Therefore, the grounding radius of the bottle is 20.85 mm and the falling angle is about 17 °.

The glass bottle 3 is obtained by increasing the radius of curvature R5 = 5 mm of the bottom of the conventional glass bottle 5 to R1 = 6 mm. The lowermost part A3 of the bottle body is located directly below the center O1 of the arcuate curve at the skirt, which is b = 19.9 mm outside the axis of the bottle. This has moved 0.95 mm inside from the lowest A5 of the conventional bottle body.
According to the conventional idea, the knurling applied to such a glass bottle is provided such that its lowermost part B4 is located directly below the center O1 of the arcuate curve at the hem as shown by a thin broken line (reference numeral 41). (Glass bottle 4 in FIG. 8). Since B4 is b = 19.9mm outside the bottle axis, the grounding radius of the bottle is 19.9mm, and the grounding radius is 0.95mm smaller than the conventional glass bottle 5. 15.5 °).

  However, the knurling 31 of the glass bottle 3 has a lowermost part (grounding part) B3 provided immediately below the center of curvature O5 of the bottom part of the conventional glass bottle 5 (radially outside the lowermost part A3 of the glass bottle 3 main body). Therefore, the contact radius is the same as that of the conventional bottle 5, a = 2.85 mm, and the falling angle is about 17 °, so that it is not easy to fall down.

As described above, the glass bottle 3 in which the lowermost part of the knurling is outside the lowermost part of the bottle main body has the same tipping angle as the conventional glass bottle, but has other problems. found. This will be described with reference to FIG.
In FIG. 7, the solid line indicates the main body shape and the knurling shape of the glass bottle 3, and the broken line indicates the main body shape and the knurling shape of the conventional glass bottle 5.
The lowermost part B3 of the knurling 31 of the glass bottle 3 has the same distance (grounding radius) from the center as the lowermost part B5 of the knurling 51 of the conventional glass bottle 5, but the outer end of the knurling 31 is more than the outer end of the knurling 51. Projecting outward, and the projecting angle θ (tangential angle of the knurling outer end) is also increased.
For this reason, it has been found that the glass bottle 3 tends to be wobbled because the outer end of the knurling comes into contact with the conveyor at the time of transfer to the conveyor in the production line or the filling line. Therefore, even if the falling angle is the same as that of the conventional glass bottle 5, there is a problem that the glass falls easily due to the fact that it is likely to wobble.

  Even if the radius of curvature of the skirt is increased to increase the water hammer strength, the present invention prevents the falling angle from becoming small and prevents the occurrence of wobbling, so that the water hammer strength of a relatively tall bottle can be reduced. It is an object to realize improvement.

In the present invention, a plurality of radial knurlings are provided in parallel along the circumferential direction along the outer peripheral edge of the bottle bottom, and the outer surface shape from the bottom to the bottom in the radial longitudinal section of the bottle body has a curvature. A portion having a radius R1 and a portion having a radius of curvature R2 larger than R1 continuous on the inside thereof , and the distance between the center of curvature O2 of R2 and the center of curvature O1 of R1 is equal to the center of the bottle , The glass bottle is characterized in that at least a part thereof is formed at a portion of the radius of curvature R2, and a lowermost part of the knurling is located radially outward from a lowermost part of the bottle body. (Claim 1)

  Since the bottom part of the knurling is outside the bottom part of the bottle body, even if the radius of curvature of the hem is increased and the bottom part of the bottle body moves inward, the bottom part of the knurling remains the same as before, Can be reduced.

  Further, in the outer surface shape from the bottom part to the bottom part in the radial longitudinal section of the bottle body, a portion having a curvature radius R2 larger than R1 is formed continuously inside the portion having the curvature radius R1, and the knurling is at least By forming a part so as to be located at a portion having the radius of curvature R2, the amount of protrusion of the outer end of the knurling can be reduced, the extension angle θ can also be reduced, and wobbling is less likely to occur.

The difference between the radius of the lowermost position of the knurling and the radius of the lowermost position of the bottle body (ab in FIG. 2) is suitably about 0.75 to 1.5 mm.
The size of R2 is suitably about 1.2 to 2 times that of R1.
The knurling may be formed at least partly at the radius of curvature R2, but it is most preferable that the entire knurling is formed at the radius of curvature R2.

  In the present invention, in the central longitudinal section along the longitudinal direction of the knurling, the radius of curvature of the outline can be configured so that the inner portion is larger than the outer portion. (Claim 2)

  If the lowermost part of the knurling is positioned outside the lowermost part of the bottle body, the position of the lowermost part of the knurling (grounding part) will be greatly moved closer to the inner side in the longitudinal direction of the knurling, and the defects (chips, cracks) ) Is likely to occur. When the radius of curvature of the outer line of the knurling is made larger at the inner part than at the outer part, the position of the lowermost part approaches the center of the knurling and the occurrence of defects due to impact is reduced.

  Further, as shown in FIG. 3, the present invention has a knurling in which the original shape of the knurling is the knurling shape of the glass bottle according to claim 1 or 2, and the bottom of the original shape is cut horizontally to form a bottom surface. It is a glass bottle characterized by (Claim 3)

  By making the knurling shape of the glass bottle of claim 1 or 2 into an original shape and forming a knurling shape in which the bottom is horizontally cut out to form a bottom surface, the grounding radius is increased, the falling angle is increased, and it is difficult to fall down. .

The longitudinal direction of the knurling may be inclined with respect to the radial direction as well as the case where the radial direction of the glass bottle is directed (Claim 4). (Claim 5)
In this case, the inclination of the knurling with respect to the radial direction is about 45 ° or less.

In the glass bottle of the present invention, the lowermost part of the outer surface of the knurling is positioned radially outward from the lowermost part of the outer surface of the bottle body where no knurling is formed, so that the radius of curvature of the hem of the bottle is increased in order to increase the water hammer strength. Even if is increased, the fall angle does not decrease.
Further, in the outer surface shape from the bottom part to the bottom part in the radial longitudinal section of the bottle body, a portion having a curvature radius R2 larger than R1 is formed continuously inside the portion having the curvature radius R1, and the knurling is at least By forming a part so as to be located at a portion having the radius of curvature R2, the amount of protrusion of the outer end of the knurling can be reduced, the extension angle θ can be reduced, and wobbling is less likely to occur.
Therefore, even if the radius of curvature of the bottle hem is increased, the bottle does not easily fall down, so that the water hammer strength can be improved by increasing the radius of curvature of the hem of the relatively tall bottle.

It is the bottom view of the glass bottle 1 of an Example, and its partial enlarged view. It is AA sectional view explanatory drawing in FIG. It is principal part sectional explanatory drawing of the glass bottle 2 of an Example. It is the bottom view of the glass bottle 1 'of an Example, and its partial enlarged view. It is a side view of a glass bottle. It is explanatory drawing of the glass bottle. It is knurling explanatory drawing of the glass bottle. It is explanatory drawing of the conventional glass bottle 5. FIG.

  As shown in FIG. 1, the knurling 11 of the glass bottle 1 of the embodiment is provided with the longitudinal direction thereof facing the radial direction of the glass bottle. In FIG. 1, the entire bottom surface of the glass bottle is shown on the upper side, and a part thereof is shown enlarged on the lower side.

FIG. 2 is an explanatory diagram of a cross section (radial direction cross section) taken along line AA in FIG. In FIG. 2, a solid line indicates a main body shape and a knurling outline (radial cross section) in the vicinity of the skirt of the glass bottle 1 of the embodiment. The broken line has shown the main body shape and knurling shape of the said glass bottle 3 as a comparative example.
The glass bottle 3 of the comparative example is a round bottle having an outer diameter of 52 mm and a height of about 151 mm, and has a curved surface having a radius of curvature R1 (= 6 mm) from the bottom to the bottom, and has an inflection point D3. The inside of the border is a concave curve on the outside. The knurling 31 is formed in a curved portion having a radius of curvature R1.
The lowermost part A3 of the bottle main body (the part other than the knurling) is located immediately below the center O1 of the arcuate curve of the skirt, and the lowermost B3 of the knurling 31 is 0.95 mm outside the lowermost part A3 of the main body. .
Further, in the contour line of the longitudinal section of the knurling 31, the radius of curvature R4 (center O4 ′) of the inner portion with the lowermost part B1 as a boundary is 2 mm larger than the radius of curvature R3 (center O3 ′) of the outer portion. Yes. For this reason, the lowermost part B1 of the knurling 13 is located near the center in the longitudinal direction of the knurling.

The glass bottle 1 of the example is also a round bottle having an outer diameter of 52 mm and a height of about 151 mm, and the curve from the skirt to the bottom is convex outside the curvature radius R1 (= 6 mm) from the skirt to the inflection point C1. Next to the curve, the inflection points C1 to D1 are convex curves outside the radius of curvature R2 (= 10 mm) larger than R1, and the inner portions from D1 are concave curves outward. ing. The curvature center O2 having the curvature radius R2 is directly above the curvature center O1 having the curvature radius R1. The entire knurling 11 is formed between the radius of curvature R1, that is, between C1 and D1.
The radial position of the lowermost part A1 of the bottle body and the radial direction position of the lowermost part B1 of the knurling are the same as A3 and B3 of the glass bottle 3, and the lowermost part B1 of the knurling 11 is 0.95 mm from the lowermost part A1 of the main body. It is on the outside. Therefore, the grounding radius and the falling angle of the glass bottle 1 and the glass bottle 3 are the same.

As apparent from FIG. 2, by providing a portion with a large curvature radius R2, the lowermost part A1 of the glass bottle 1 and the lowermost part B1 of the knurling are respectively lower than the lowermost part A3 of the glass bottle 3 and the lowermost part B3 of the knurling. As a result, the knurling 11 has an outer end located on the inner side (smaller overhang amount) and a smaller overhang angle than the knurling 31.
Thereby, compared with the glass bottle 3, the glass bottle 1 has less wobbling of the bottle when the outer end of the knurling contacts the conveyor in the production line or the filling line, and is less likely to fall.

Further, the radius of curvature R4 (curvature center O4) of the inner portion of the knurling 11 with the lowermost part B1 as the boundary and the radius of curvature R3 (curvature center O3) of the outer portion are the same as R4 and R3 of the glass bottle 3. (R4> R3), and the lowermost part B1 of the knurling is positioned above B3, so that O4 and O3 are positioned above O4 ′ and O3 ′, respectively.
Similarly to the knurling 31, the knurling 11 has a radius of curvature R4 of the inner portion larger than a radius of curvature R3 of the outer portion, so that the lowermost part B1 of the knurling 11 is located near the center in the longitudinal direction of the knurling.

The knurling 21 of the glass bottle 2 in FIG. 3 has a shape in which the shape of the knurling 11 in FIG. 2 is the original shape 22, and the bottom is cut out by a horizontal plane s to form a bottom surface 23. Since the distance from the outermost position B2 of the bottom surface 23 to the center is the grounding radius, the grounding radius and the falling angle are larger than those of the glass bottle 1, and it is further difficult to fall.
However, if the area of the bottom surface 23 becomes too large, the thermal shock when the glass bottle immediately after molding is placed on the conveyor and the mechanical shock in the subsequent process may be increased, and the knurling may be damaged. The difference between the height of s and the height of the lowest point B1 of the original shape 22 is preferably about 0.2 mm or less, and most preferably 0.05 to 0.1 mm.

FIG. 4 shows the bottom of a glass bottle 1 'according to another embodiment, and the knurling 11' is provided with its longitudinal direction inclined with respect to the radial direction of the glass bottle.
Thus, the knurling of the present invention may be inclined with respect to the radial direction.
The cross-sectional shape of the knurling 11 ′ and the positional relationship with respect to the bottle body are the same as in the case of the knurling 11 of the glass bottle 1.
Similarly to the above embodiment, in the central longitudinal section (BB cross section) along the longitudinal direction of the knurling 11 ′, the inner radius of the outer wall is larger than the outer radius.

1 Glass Bottle 11 Knurling 1 'Glass Bottle 11' Knurling 2 Glass Bottle 21 Knurling 22 Original Shape 23 Bottom 3 Glass Bottle 31 Knurling 4 Glass Bottle 41 Knurling 5 Glass Bottle 51 Knurling

Claims (5)

A plurality of radial knurlings are provided in parallel along the circumferential direction along the outer peripheral edge of the bottle bottom, and the outer surface shape from the bottom to the bottom in the radial longitudinal section of the bottle body is a portion having a radius of curvature R1. A radius of curvature R2 larger than R1 continuous on the inside thereof , and the distance between the center of curvature O2 of R2 and the center of curvature O1 of R1 from the bottle center is equal, and at least a part of the knurling is A glass bottle which is formed at a portion of the radius of curvature R2 and wherein the lowermost part of the knurling is located radially outside the lowermost part of the bottle body.   2. The glass bottle according to claim 1, wherein, in a central longitudinal section along a longitudinal direction of the knurling, an inner portion has a radius of curvature of a contour line larger than that of an outer portion.   An original shape of the knurling is the knurling shape of the glass bottle according to claim 1 or 2, wherein the glass bottle has a knurling in which the bottom of the original shape is cut horizontally to form a bottom surface.   The glass bottle according to claim 1, wherein a longitudinal direction of the knurling faces a radial direction of the glass bottle.   The glass bottle according to claim 1, wherein a longitudinal direction of the knurling is inclined with respect to a radial direction of the glass bottle.

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