JP2018140827A - Bottle type can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bottle type can which can be thinned without losing buckling strength and can be reduced in weight.SOLUTION: In the bottle type can, an S-shaped bead part 12 and a straight part 13 having a predetermined outer shape are formed in order from the side of a coupler part 11 between the coupler part 11 and the shoulder part 8, wherein the S-shaped bead part 12 is formed continuously with the concave part 11b and has a convex bead part 12a having an outer diameter larger than that of the concave part 11b and a recess part formed in the inner side of a neck part 6 continuous to the lower side of the convex bead part 12a and a concave bead part 12b having a cross-sectional shape symmetrical to the cross-sectional shape of the convex bead part 12a, and the straight part 13 is formed continuously with the lower side of the concave bead part 12b, with a neck part of six necks between the concave bead part 12b and the shoulder part 8, with 1 mm or more and 7 mm or less length in the center axis line direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a can molded into a bottle shape using a metal plate as a raw material, and more particularly to a bottle-shaped can that can be resealed by screwing a cap onto a cylindrical mouth portion.

  Conventionally, a metal plate such as an aluminum alloy is drawn and ironed to form a cup-shaped or cylindrical intermediate body with a bottom, and the opening end of the intermediate body is gradually reduced in diameter to form a cylindrical shape. A bottle-shaped can with a nose is known. The curl portion is formed by winding the tip of the mouth portion outward, and the male screw portion and the turnbuckle portion are formed by screw molding or the like on the mouth portion. Roll-on capping is known as a method for sealing a bottle-shaped can of this type by attaching a cap. In roll-on capping, a cylindrical cap rough shape member having a top plate portion that closes the curl portion is placed on the mouth portion, the cap rough shape material is pressed against the curl portion by a pressing pad, and the corner portion is squeezed by a pressure block. Adhere the inner liner to the curl. In this state, the cylindrical portion (skirt portion) of the rough cap shape member is squeezed along the male screw portion of the mouth portion by a screw forming roll to form a female screw portion, and a pill provided at the lower end portion of the cylindrical portion. The fur-proof band is wound on the lower side of the turnip portion by a hem fastening roll.

  In this way, the mouth of the bottle-shaped can has a pressing force in the axial direction during capping (axial load or plugging force), a lateral force (lateral load) or compressive force by each roll, and each The torsional load caused by the relative rotation of the roll while forming is combined to act. Therefore, a large stress acts on the base portion of the mouth neck (boundary portion with the shoulder portion), and this portion is easily deformed. In particular, if the shoulder is curved or bulging into a dome shape or convex curved surface, the angle of the tangent (tangent to the generatrix of the convex curved surface) at the top of the shoulder to which the mouth part is connected (can central axis of the tangent) Angle). Therefore, the upper portion of the shoulder is easily deformed by the above-described plugging force, or the portion from the neck portion to the shoulder portion is likely to buckle. Such deformation (hereinafter sometimes simply referred to as buckling) may be caused not only by the striking force but also by deformation of the portion connecting the mouth and shoulder. That is, the screw forming roll and the hem fastening roll press a part of the outer peripheral portion of the skirt portion and the mouth portion of the cap from the outside in the radial direction toward the center portion. Therefore, these loads are loads in the direction of crushing the mouth part, and when the rigidity of the mouth part is low with respect to the load, the mouth part is deformed into an elliptical cross section. When such a deformation extends from the neck portion to the upper shoulder portion, the rigidity with respect to the striking force in the portion where the curvature in the circumferential direction around the central axis is reduced becomes low, and the portion is likely to buckle.

  In order to increase the rigidity against buckling as described above, the wall thickness of the neck and shoulders may be increased, but it is difficult to increase the wall thickness due to demands for cost reduction and weight reduction. In recent years, it is actually desirable to reduce the wall thickness without sacrificing rigidity. In particular, in a bottle-shaped can manufactured in the same process as a DI can, the diameter of the opening end side of the cylindrical intermediate body with a bottom is gradually reduced to form a shoulder portion and a mouth portion. The wall thickness is thinner than the mouth, and it is difficult to ensure its rigidity.

  Therefore, for example, in the bottle-type can described in Patent Document 1, the shoulder portion is formed by forming an annular recess and a projection centering on the central axis of the can at the upper portion of the shoulder portion (portion on the mouth portion side). The rigidity of the upper part is improved. Patent Document 2 describes a configuration in which lateral strength is improved by forming a bead portion protruding inward of the mouth portion at a bulging portion connected to the lower side of the skirt valley portion. Note that Patent Document 2 also shows an example in which a linear portion is provided below the bead portion. However, Patent Document 2 does not describe any specific shape and size of the straight portion, and no action / effect by providing the straight portion.

Japanese Patent No. 3561696 JP 2006-196332 A

  According to the configuration described in Patent Document 1, the rigidity of the upper shoulder portion can be improved. However, in roll-on capping, the mouth part is deformed into an oval shape by a screw forming roll or a hem fastening roll, which may cause buckling, whereas the configuration described in Patent Document 1 Then, it is difficult to improve the rigidity of the mouth part against so-called elliptical deformation, and even if the buckling strength of the upper part of the shoulder can be increased, there is still room for improvement. Moreover, since the structure currently described in patent document 1 is a structure which forms a cyclic | annular convex part and a recessed part in a shoulder upper part, the shape of the upper shoulder part which is easy to enter into a consumer's eyes is the conventional smooth The shape must be different from the shape, and there are inconveniences such as the necessity to change the design of the bottle-type can or the restriction on the degree of freedom of design.

  On the other hand, according to the description of Patent Document 2, it is said that local deformation can be prevented by improving the strength against the lateral load by the roll. However, the bead portion is a portion in which a part of the bulging portion is recessed inwardly, and its width (size in the direction of the central axis of the mouth portion) is smaller than the width of the bulging portion, and the height is also high. Since it is low, the rigidity against so-called elliptical deformation due to the roll is not necessarily high enough, and even if the rigidity against lateral load is improved, there is still room for improvement in terms of improving the buckling strength.

  The present invention has been made paying attention to the above technical problem, and aims to provide a bottle-shaped can that can improve the buckling strength and can be reduced in thickness or weight. is there.

  In order to achieve the above object, the present invention has a trunk portion and a bottom portion that are integrally formed, and a shoulder portion whose outer diameter decreases toward the upper side is formed continuously at the upper portion of the trunk portion, A cylindrical mouth portion is continuously formed on the upper portion of the shoulder portion. The mouth portion includes a male screw portion, a bulge portion formed continuously below the male screw portion, and the bulge. In a bottle-type can in which a concave portion having an outer diameter smaller than the protruding portion is formed, an S-shaped bead portion and an outer diameter are constant between the concave portion and the shoulder portion in order from the concave portion side. The S-shaped bead portion is formed continuously with the concave portion and has a larger outer diameter than the concave portion, and the mouth portion continuously below the convex bead portion. And the cross-sectional shape of the convex bead portion is A concave bead portion having a nominal shape, and the straight portion is continuous with the lower side of the concave bead portion and is long between the concave bead portion and the shoulder portion in the direction of the central axis of the mouth portion. A bottle-shaped can characterized by having a length of 1 mm or more and 7 mm or less.

  In the present invention, the straight portion may have an outer diameter of 26 mm or more and 40 mm or less, and a thickness of 0.28 mm or more and 0.34 mm or less.

  In the present invention, the convex bead portion has an outer diameter that is equal to or smaller than the outer diameter of the straight portion and larger than the outer diameter of the concave portion in the cabra portion, and the outer diameter of the concave bead portion is equal to that in the cabra portion. It may be larger than the outer diameter of the concave portion and smaller than the outer diameter of the convex bead portion and the outer diameter of the straight portion.

  Furthermore, in the present invention, the height of the S-shaped bead portion, which is half the difference between the outer diameter of the convex bead portion and the outer diameter of the concave bead portion, is 0.7 mm or more and 1.5 mm or less. Can do.

  In the present invention, the shoulder may be formed in a convex curved shape that is raised upward.

  In the present invention, the boundary portion connecting the straight portion and the shoulder portion may be formed so that the cross-sectional shape forms an arc shape that is recessed toward the inside of the mouth portion or the shoulder portion.

  In the present invention, the arcuate radius in the boundary portion may be 2 mm or more and 4 mm or less.

  The bottle-type can according to the present invention has an S-shaped bead portion between the turnip portion and the shoulder portion, and the S-shaped bead portion has a symmetrical cross-sectional shape and is continuous with each other. Because it is formed by convex and concave bead parts, it does not easily deform into an elliptical shape even when subjected to a lateral load during capping, and by forming a concave bead part, the axial direction during capping Since a portion receiving the load obliquely upward is generated, the strength against the axial load at the time of capping, that is, the buckling strength can be improved. Further, since the cylindrical straight portion having a length of 1 mm to 7 mm (dimension in the axial direction) is provided between the S-shaped bead portion and the shoulder portion, the S-shaped bead portion or the concave bead portion is provided. It is possible to avoid or suppress the distortion and stress caused by forming the upper portion of the shoulder portion from being avoided or suppressed, thereby avoiding a decrease in the buckling strength or improving the buckling strength. Since the buckling strength can be improved by such a shape or structure, the overall thickness of the bottle-type can can be reduced, and the cost and weight can be reduced.

It is a schematic diagram for demonstrating the process in which a bottle type can is manufactured by drawing and ironing. It is a front view of the bottle-shaped can which concerns on this invention. It is a figure which shows typically the state which has attached the cap by roll-on capping to a mouth part. It is a partial expanded sectional view which shows an example of a S-shaped bead part and a straight part. It is sectional drawing which expanded a part of FIG. 4 further. It is a figure explaining how stress (reaction force) arises when a lateral load by a roll such as a hem fastening roll is applied to the mouth, and (a) shows an example having an S-shaped bead, b) shows an example in which the S-shaped bead portion is not provided. The bottle type can used as an Example is shown, (a) is a front view, (b) is sectional drawing of the part which reaches from a cabra part to a shoulder part. The bottle type can of the comparative example 1 is shown, (a) is a front view, (b) is sectional drawing of the part which reaches a shoulder part from a cabra part. The bottle type can of the comparative example 2 is shown, (a) is a front view, (b) is sectional drawing of the part which reaches a shoulder part from a cabra part. It is a graph which shows collectively the data and buckling strength about the bottle-type can of an Example and each comparative example.

  The bottle-shaped can according to the present invention is a metal can made of a metal plate such as an aluminum plate or a resin-coated aluminum plate, and the bottom plate and the body portion are integrated through a molding process such as drawing or ironing. The intermediate body is formed, and the opening end side thereof is subjected to necking processing and screw / curl processing. FIG. 1 schematically shows the manufacturing process. A cylindrical body 4 in which the bottom 2 and the body 3 are integrated by subjecting the metal plate 1 as a material to drawing, redrawing, and redrawing. , And further ironing is performed to increase the depth of the cylindrical body 4. At that time, doming is applied to the bottom 2. The opening end side (upper end side) of the cylindrical body 4 is cut out by trimming. Subsequently, it is set as the intermediate body 5 through a coating process. The opening end side of the intermediate body 5 is gradually reduced in diameter by necking to form the mouth part 6, and the mouth part 6 is subjected to screw / curl processing to form a bottle-type can 7.

  The bottle-shaped can 7 according to the present invention shown in FIG. 2 is manufactured through the steps described above as an example. Accordingly, while the body 3 is subjected to drawing / ironing, the mouth 6 and the shoulder 8 between the body 3 and the mouth 6 are reduced in diameter. On the other hand, the thickness of the shoulder portion 8 and the mouth portion 6 is relatively thick. An example of the bottle-shaped can 7 is a bottle-shaped can having an outer diameter of the body portion 3 of 53 mm (name: 202 diameter) or 66 mm (name: 211 diameter) and an outer diameter of the mouth portion 6 of 28 mm to 38 mm.

  The bottle-type can 7 is configured to be resealable (resealed) by attaching a cap (not shown) to the neck 6. That is, a curled part 9 wound outward is formed at the opening end of the mouth part 6, and a male screw part 10 is formed under the curled part 9. A turnip portion 11 is formed below the male screw portion 10. The turnip portion 11 engages with a pilfer proof band (not shown) provided at the lower end of the skirt portion (cylindrical portion) constituting the cap, and the pill fur proof when the cap is removed. It is a part for breaking the band from the cap and leaving it on the mouth part 6, and a bulging part 11 a having an outer diameter of the thread in the male thread part 10, and the entire circumference of the mouth part 6 on the lower side. And a formed recess 11b. The recess 11b is made clear to the consumer that the pilfer proof band separated from the cap and left on the mouthpiece 6 is loosely fitted so that it is detached from the cap, as will be described later. It is provided so that the tool for hem fastening can enter.

  An S-shaped bead portion 12 is formed below the concave portion 11b. Further, a straight portion 13 is formed between the S-shaped bead portion 12 and the shoulder portion 8. Detailed configurations of the S-shaped bead portion 12 and the straight portion 13 will be described later.

  FIG. 3 schematically shows a state in which the cap 14 is attached to the mouth portion 6 of the bottle-type can 7 by roll-on capping. The cap 14 is put on the mouth 6 of the bottle-shaped can 7 that is upright with the mouth 6 facing upward, and the cap 14 is pressed by the pressure head 15. The pressure head 15 is integrally formed with a center-side pressing pad and an outer peripheral pressure block. The corner portion of the cap 14 is pressed and deformed by the pressure block toward the curled portion 9, and the liner 16 provided on the inner surface of the cap 14 is brought into close contact with the curled portion 9 so as to be sandwiched between the curled portion 9. When the pressing pad comes into contact with the top surface of the cap, the cap 13 is pressed in the direction of the central axis of the bottle-type can 7 to give a stoppering pressure.

  In addition, the skirt portion (cylindrical portion) of the cap 14 is pressed from the outside by the screw forming roll 17 and the mouth portion 6 and the screw forming roll 17 are relatively rotated in this state, thereby the skirt portion. Is pressed against the male screw part 10 formed on the mouth part 6 and deformed along the thread groove of the male screw part 10 to form the female screw part. Further, the lower end portion of the skirt portion of the cap 14 (that is, the portion corresponding to the pill fur proof band) is brought into close contact with the above-described turnip portion 11 by the hem fastening roll 18 that relatively turns on the outer peripheral side of the mouth portion 6. And squeezed to engage the lower side of the bulging portion 11a. Therefore, during roll-on capping, as shown by a thick arrow in FIG. 3, a load (plugging force) A in the direction along the central axis, and a twisting force B due to the relative rotation of the bottle-shaped can 7, The horizontal lateral force C by the rolls 17 and 18 acts in combination. In order to prevent or suppress buckling deformation due to such a combined load, the aforementioned S-shaped bead portion 12 and straight portion 13 are formed on the mouth portion 6.

  4 and 5 are partially enlarged cross-sectional views showing examples of the S-shaped bead portion 12 and the straight portion 13, and the S-shaped bead portion 12 is continuous to the lower side of the concave portion 11b in the turnable portion 11, and is the mouth portion. 6 is formed by a convex bead portion 12a protruding outward in the radial direction and a concave bead portion 12b which is continuous to the lower side of the convex bead portion 12a and is recessed inside the mouthpiece portion 6. These bead portions 12a and 12b are portions having a shape corresponding to an annular groove formed over the entire circumference of the neck portion 6, and the convex bead portion 12a is shown in an enlarged sectional view in FIG. In addition, it is formed so as to form an arc shape with a predetermined radius Ra (for example, 1 mm to 2 mm), and is a bead when viewed from the outside of the mouth part 6. The concave bead portion 12b is formed so as to form an arc shape with a predetermined radius Ra as shown in an enlarged view in FIG. 5, and has a concave groove shape when viewed from the outside of the mouth neck portion 6. The inside of the neck 6 is a bead. That is, the convex bead portion 12 a is a convex bead having an arc-shaped cross section in which the center of curvature exists inside the mouth neck portion 6 when viewed from the outside of the mouth neck portion 6. It is a concave groove having an arc-shaped cross section in which the center of curvature exists outside the mouth neck portion 6 when viewed from the outside. The convex bead portion 12a and the concave bead portion 12b are connected at a location where the tangent line is approximately 45 ° to 30 ° (an angle with respect to the central axis of the bottle can 7). This is to increase the strength against the vertical plugging force that acts during capping. Accordingly, the cross-sectional shape of these portions is an “S” shape. In other words, the width and depth of the convex bead portion 12a and the concave bead portion 12b are equal to each other, and their cross-sectional shapes are symmetrical to each other.

  Further, the S-shaped bead portion 12 is formed in the diameter direction of the neck portion 6, outside the concave portion 11 b and inside the straight portion 13, that is, between the concave portion 11 b and the straight portion 13. 4 and 5, when the outer diameter of the recess 11b (the outer diameter of the bottom portion of the recess 11b) is D1, and the outer diameter of the straight portion 13 is D4, the maximum outer diameter of the S-shaped bead portion 12 ( The outer diameter D2 of the top of the convex bead portion 12a is substantially equal to the outer diameter D4 of the straight portion 13, and the minimum outer diameter of the S-shaped bead portion 12 (the outer diameter of the bottom portion of the concave bead portion 12b) D3 is the concave portion 11b. Is substantially equal to the outer diameter D1. Therefore, even if the S-shaped bead portion 12 is provided, the S-shaped bead portion 12 does not protrude to the outer peripheral side from the straight portion 13 or the turnable portion 11, thereby avoiding troubles in handling the bottle-type can 7 or capping work. it can. The height H of the S-shaped bead portion 12 is half of the difference between the outer diameter D2 of the convex bead portion 12a and the outer diameter D3 of the concave bead portion 12b. In the present invention, the height H is 0. 7 mm to 1.5 mm. The portion where the S-shaped bead portion 12 transitions to the concave portion 11b and the portion where the S-shaped bead portion 12 transitions to the straight portion 13 are formed so that the cross-sectional shape is an arc shape so that stress concentration does not occur. It has become. Moreover, the part (boundary part) 19 which has connected the straight part 13 and the shoulder part 8 becomes a concave shape in which the center of curvature is outside the mouth part 6, and the curvature radius of the concave arc of the cross section is 2 mm. Above and below 4 mm.

  The straight portion 13 is formed in order to avoid or suppress the influence of deformation, stress, and the like associated with the formation of the S-shaped bead portion 12 or the elliptical deformation of the S-shaped bead portion 12 on the shoulder portion 8. It is a cylindrical part. Therefore, if the length L in the axial direction of the straight portion 13 is long, the influence on the shoulder portion 8 from the S-shaped bead portion 12 can be avoided. However, the height of the bottle-shaped can 7 depends on the filling equipment, the carton case for conveyance or the automatic Since the length of the straight portion 13 is lengthened due to the restriction of the guide size and the like in the vending machine, the length of the trunk portion 3 is shortened and the internal capacity is reduced. Conversely, the length L of the straight portion 13 is reduced. If it is short, the influence on the shoulder portion 8 from the S-shaped bead portion 12 cannot be avoided or suppressed, and the effect of improving the buckling strength cannot be obtained. Therefore, in the present invention, the length L of the straight portion 13 is set to 1 mm to 7 mm. Moreover, the outer diameter of the straight part 13 is substantially equal to the outer diameter of the above-described turnip part 11 (the outer diameter of the bulging part 11a). In other words, a cylindrical portion having an outer diameter of the straight portion 13 is formed on the upper portion of the shoulder portion 8 as the mouth portion 6, and the root portion of the cylindrical mouth portion 6 (the portion on the shoulder portion 8 side) is 1 mm. The above-described S-shaped bead portion 12, turnip portion 11, male screw portion 10, and the like are formed on the upper portion of the straight portion 13 with a thickness of ˜7 mm. In the present invention, the thickness (wall thickness) t of the straight portion 13 is set to 0.28 mm to 0.34 mm. As described above, since the straight portion 13 is formed by gradually reducing the diameter of the shoulder portion 8, the thickness thereof is thicker than the thickness of the shoulder portion 8 (particularly on the body portion 3 side). In other words, by making the straight portion 13 thick as described above, it is possible to ensure buckling strength, and to make the shoulder portion 8 and the trunk portion 3 thinner than this, thereby reducing the weight and cost. it can.

  The bottle-shaped can 7 according to the present invention has a high buckling strength because the S-shaped bead portion 12 and the straight portion 13 are provided in the shoulder portion 8 side portion of the mouth neck portion 6. Therefore, since it is less necessary to form a taper shape to improve the buckling strength of the shoulder portion 8, the shoulder portion 8 has a dome shape having a cross-sectional shape of a convex arc shape with a predetermined radius R as shown in FIG. Is formed. That is, in the present invention, there are few restrictions on the shape of the shoulder portion 8, and the diversification of the shape is achieved.

  In the bottle type can 7 according to the present invention, by providing the S-shaped bead portion 12 and the straight portion 13, the buckling strength with respect to the striking force (pressing force in the axial direction) at the time of roll-on capping has been conventionally increased. The effect can be explained as follows. FIG. 6 is a diagram for explaining how a stress (reaction force) Fr is generated when a lateral load F is applied to the neck portion 6 by a roll such as the hem fastening roll 18, and (a) is an S-shaped bead portion 12. (B) shows an example in which the S-shaped bead portion 12 is not provided. In the case where the S-shaped bead portion 12 is provided, the upper and lower sides of the convex bead portion 12a become an obliquely upward inclined surface and an obliquely downward inclined surface, and thus the reaction force in the direction along these inclined surfaces. Fr is generated, and the mouth portion 6 is hardly deformed in the radial direction. That is, the elliptical deformation of the mouth part 6 hardly occurs. Each inclined surface can also generate a reaction force as a component force in the axial direction (vertical direction), and a resistance force to the plugging force is generated. As described above, since the generation of stress and distortion due to elliptic deformation is avoided or suppressed, the stress concentration when the capping force is applied is alleviated and buckling is less likely to occur. Further, by forming the S-shaped bead portion 12, even if the influence of deformation or residual stress at the time of processing may reach the vicinity of the S-shaped bead portion 12, the provision of the straight portion 13 Such an influence is avoided or suppressed from reaching the upper portion of the shoulder portion 8. Therefore, local stress concentration does not occur at the upper portion of the shoulder portion 8, and it is difficult to buckle at this point as well, and the buckling strength against the plugging force is improved.

  On the other hand, in the example that does not include the S-shaped bead portion 12 shown in (b), the reaction force Fr generated on the shoulder portion 8 side becomes a force directed in the radial direction of the mouth portion 6, and is simply applied to the mouth portion 6. Bending stress or compressive stress. For this reason, elliptical deformation of the mouth portion 6 is likely to occur, and resistance against the axially plugging force is unlikely to occur. Therefore, the buckling strength improving action as described with reference to (a) does not occur.

  Next, Examples and Comparative Examples performed for confirming the effects of the present invention will be shown.

  FIG. 7 shows a bottle type can used as an example. (A) is a front view, (b) is a cross-sectional view of a portion from the cabra portion 11 to the shoulder portion 8. The data for this bottle-shaped can is as follows. The thickness (original plate thickness) of the aluminum plate as the material is 0.35 mm, the outer diameter (can outer diameter) of the body 3 is 66 mm, the height (product height) is 131 mm, and the position of the shoulder 8 (from the bottom) ) Is 76 mm, the metal thickness on the thick wall (thickest part) after drawing and ironing (after BM) is 0.22 mm, and the metal thickness on the thin wall (thinnest part) after BM is 0.145 mm. The thickness (wall thickness) of the mouth part 6 after the product is 0.32 mm, the outer diameter of the turnable part 11 (outer diameter of the bulged part 11a) D4 is 37.8 mm, and the outer diameter D1 of the concave part 11b of the turnable part 11 Is 35.4 mm, the length of the mouth part 6 is 28 mm, the radius of curvature Ra of each bead part 12a, 12b constituting the S-shaped bead part 12 is 1.5 mm, the length of the straight part 13 is 1.5 mm, The content is 290ml. This bottle type can was analyzed for buckling strength. The analysis showed that the buckling force was exerted on the bottle-shaped can, the lateral load (about 118N as an example) by the roll for screw forming and hem tightening, and the torsional force accompanying capping, resulting in obvious buckling. This was done by calculating the plugging force. The buckling strength was 1624.2 N (Newton).

Comparative Example 1

  A front view of the bottle-shaped can of Comparative Example 1 is shown in FIG. 8 (a), and a cross-sectional view of the portion from the turnip 11 to the shoulder 8 is shown in FIG. 8 (b). The bottle-shaped can of the comparative example 1 is not provided with the S-shaped bead portion 12, and the straight portion 13 is longer than that. Specifically, the portion between the turnip portion 11 and the shoulder portion 8 is the straight portion 13, and its length is 6 mm. Other data on the bottle-shaped can of Comparative Example 1 is the same as the data in the above-described embodiment except that the S-shaped bead portion 12 is not provided. When the buckling strength of the bottle-shaped can of Comparative Example 1 was analyzed, the buckling strength was 1535.9 N (Newton).

Comparative Example 2

  FIG. 9A shows a front view of the bottle-shaped can of Comparative Example 2, and FIG. 9B shows a cross-sectional view of the portion from the turnip 11 to the shoulder 8. Although the bottle-shaped can of Comparative Example 2 is provided with the S-shaped bead portion 12, the straight portion 13 is not provided. Specifically, the portion between the turnip portion 11 and the shoulder portion 8 is an S-shaped bead portion 12, and the size and shape thereof are the same as those of the bottle-type cans of the above-described embodiments. Other data on the bottle-shaped can of Comparative Example 2 is the same as the data in the above-described embodiment except that the straight portion 13 is not provided. When the bottle-shaped can of Comparative Example 2 was analyzed for buckling strength, the buckling strength was 1597.3 N (Newton).

  The data and buckling strength for the bottle-type cans of the above-described Examples and Comparative Examples 1 and 2 are collectively shown in FIG. The buckling of the bottle-shaped can occurs at the upper part of the shoulder, more specifically at the part connected to the mouth part, and the cause is considered to be the stress concentration due to the above-mentioned combined load at the time of roll-on capping. In the example in which only the straight portion 13 is formed as in the bottle-shaped can of Comparative Example 1, the buckling strength is lower than that of Comparative Example 2 including the S-shaped bead portion 12 and the bottle-shaped can of the Example. This is thought to be due to the fact that elliptical deformation occurs in the neck 6 due to lateral load, and stress that concentrates locally on the upper part of the shoulder increases, and bending stress due to lateral load concentrates on the upper part of the shoulder. .

  Moreover, although the buckling strength of the bottle-type can of Comparative Example 2 was improved as compared with the bottle-type can of Comparative Example 1, it was not possible to obtain the buckling strength as much as the bottle-type can of the Example. In Comparative Example 2, since the S-shaped bead portion 12 is provided, the elliptical deformation of the neck portion 6 is suppressed, and the bending stress due to the lateral load is also shared by the portion of the S-shaped bead portion 12. It is considered that the local stress concentration at the upper portion of the shoulder portion 8 is alleviated, and as a result, the buckling strength is improved as compared with the bottle-type can of Comparative Example 1. However, the buckling strength is lower than that of the bottle type can of the embodiment, and there is room for improvement in order to reduce the thickness and weight of the bottle type can.

  In the bottle type can of the example, the buckling strength was further improved to that of Comparative Example 2 or more. Although the portion connected to the upper side of the shoulder portion 8 is the straight portion 13, the buckling strength is improved compared to the comparative example 1 and the buckling strength is compared to the comparative example 2 in which only the S-shaped bead portion 12 is provided. Inferring that the strength is improved, it is considered that the S-shaped bead portion 12 and the straight portion 13 have produced some synergistic action. According to the knowledge of the present inventors, when some forming process is performed on a metal plate, it is normal that the part adjacent to the processed part is affected by distortion or residual stress. It is considered that the straight portion 13 in the bottle type can of the example blocks or suppresses the influence on the shoulder portion 8 due to the formation of the S-shaped bead portion 12. Therefore, in the comparative example 2, although the S-shaped bead portion 12 suppresses the elliptical deformation of the neck portion 6, the influence when the S-shaped bead portion 12 is formed is on the upper portion of the shoulder portion 8, and this is the buckling strength. In contrast, in the bottle-type can according to the embodiment of the present invention, the effect of impairing the buckling strength can be blocked or suppressed by the straight portion 13, and as a result, the buckling strength can be further increased. It is thought that it was possible to improve. Therefore, according to the present invention, the buckling strength can be improved by the shape or structure of the mouth portion 6, so that the bottle-shaped can can be reduced in thickness and weight. In addition, since it is not necessary to provide a new processing part such as a bead on the shoulder, it is possible to prevent the freedom of design from being hindered or restricted.

  Note that the present invention is not limited to the specific examples described above, and the internal volume may be set as appropriate, and the inclination angle of the shoulder portion, the outer diameter and length of the mouth portion, etc. are within the scope of the present invention. As long as it does not deviate from, it may set suitably as needed.

  6 ... Mouth part, 7 ... Bottle type can, 8 ... Shoulder part, 10 ... Male screw part, 11 ... Cabra part, 11a ... Swelling part, 11b ... Recessed part, 12 ... S bead part, 12a ... Convex bead part, 12b DESCRIPTION OF SYMBOLS ... Concave bead part, 13 ... Straight part, 17 ... Roll for screw forming, 18 ... Roll for hem fastening, 19 ... Border part.

Claims (7)

The body part and the bottom part are integrally formed, and a shoulder part whose outer diameter decreases toward the upper side is formed continuously at the upper part of the body part, and further, a cylindrical mouth part is continuous at the upper part of the shoulder part. The mouth part includes a male screw part, a bulge part formed continuously below the male screw part, and a turnip part comprising a recess having a smaller outer diameter than the bulge part; In the bottle-shaped can where is formed,
Between the turnip portion and the shoulder portion, an S-shaped bead portion and a straight portion with a constant outer diameter are formed in order from the turnover portion side,
The S-shaped bead portion is formed so as to be continuous with the concave portion and has a larger outer diameter than the concave portion, and is continuously formed below the convex bead portion so as to be recessed inside the mouth portion. The cross-sectional shape has a concave bead portion that is symmetrical with the cross-sectional shape of the convex bead portion,
The straight portion is continuously formed below the concave bead portion and has a length of 1 mm or more and 7 mm or less in the central axis direction of the mouth portion between the concave bead portion and the shoulder portion. Bottle type can characterized by being made. The bottle-shaped can according to claim 1,
The straight portion has an outer diameter of 26 mm or more and 40 mm or less, and a thickness of 0.28 mm or more and 0.34 mm or less. The bottle-shaped can according to claim 1 or 2,
The outer diameter of the convex bead portion is equal to or smaller than the outer diameter of the straight portion and larger than the outer diameter of the concave portion in the turnip portion,
The bottle-shaped can characterized in that an outer diameter of the concave bead portion is equal to or larger than an outer diameter of the concave portion in the turnip portion and smaller than an outer diameter of the convex bead portion and an outer diameter of the straight portion. In the bottle-shaped can according to any one of claims 1 to 3,
The bottle shape, wherein the height of the S-shaped bead portion, which is half the difference between the outer diameter of the convex bead portion and the outer diameter of the concave bead portion, is 0.7 mm or more and 1.5 mm or less. can. In the bottle-shaped can according to any one of claims 1 to 4,
The bottle-shaped can characterized by the above-mentioned shoulder part being formed in the convex curved surface shape which rose up. In the bottle type can according to any one of claims 1 to 5,
The boundary part connecting the straight part and the shoulder part is formed so that the cross-sectional shape forms an arc shape that is recessed toward the inside of the mouth part or the shoulder part. can. The bottle-shaped can according to claim 6,
The bottle-shaped can characterized in that the arc-shaped radius in the boundary portion is 2 mm or more and 4 mm or less.

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