JP7262344B2

JP7262344B2 - bottle can

Info

Publication number: JP7262344B2
Application number: JP2019155932A
Authority: JP
Inventors: 英泰武藤; 元彦鎌田
Original assignee: アルテミラ製缶株式会社
Priority date: 2019-08-28
Filing date: 2019-08-28
Publication date: 2023-04-21
Anticipated expiration: 2037-03-24
Also published as: JP2019199307A

Description

本発明は、缶軸を中心とする有底筒状の缶本体の上端部に、雄ネジ部と膨出部とを備えてキャップが取り付けられる円筒状のキャップ取付部が形成された金属製のボトル缶に関するものである。 The present invention is a metal can body in which a cylindrical cap mounting portion having a male screw portion and a bulging portion to which a cap is attached is formed at the upper end portion of a bottomed cylindrical can body centered on the can axis. It relates to bottle cans.

このようなボトル缶として、例えば特許文献１には、筒状の胴部と、該胴部の上部に、缶軸に対して傾斜しかつ上方に向かって縮径した肩部と、該肩部の上部に、上方に向かって延びる筒状の口部（キャップ取付部）とからなり、該口部は、肩部の上端に接続する基部と、該基部に接続するスカート谷部と、該スカート谷部に接続するスカート部（膨出部）と、該スカート部に接続するネジ部（雄ネジ部）とを有するアルミニウム等の金属製のものが記載されている。ここで、この特許文献１の図１では、雄ネジ部の終端（下端）は缶軸方向において膨出部の中にまで到達している。 As such a bottle-shaped can, for example, Patent Document 1 discloses a cylindrical body, a shoulder section in the upper part of the body section, which is inclined with respect to the can axis and whose diameter is reduced upward, and the shoulder section. consists of a cylindrical mouth portion (cap attachment portion) extending upward, the mouth portion comprising a base portion connected to the upper end of the shoulder portion, a skirt valley portion connected to the base portion, and the skirt A metal such as aluminum having a skirt portion (bulging portion) connected to the valley portion and a screw portion (male screw portion) connected to the skirt portion is described. Here, in FIG. 1 of Patent Document 1, the terminal end (lower end) of the male screw portion reaches into the bulging portion in the can axial direction.

こうしたボトル缶は、内部に飲料等が充填された後、キャップ取付部に同じくアルミニウム等の金属製のキャップが被せられ、ブロックにより缶軸方向に荷重がかけられることによってキャップが絞り加工されるとともに、スレッドローラーによって缶軸に垂直な方向に向けて内周側にキャップに荷重がかけられることにより上記雄ネジ部に倣うように雌ネジ部が成形され、さらにスカートローラーによってキャップ下端の開放端部が内周側に押圧されることにより膨出部下側の縮径部に巻き締められて封止される。 After the inside of such a bottle-can is filled with a beverage or the like, the cap mounting portion is covered with a cap made of metal such as aluminum, and the cap is drawn by applying a load in the axial direction of the can by a block. A load is applied to the inner periphery of the cap in a direction perpendicular to the can axis by a thread roller to form a female threaded portion so as to follow the male threaded portion, and a skirt roller is used to form the open end of the lower end of the cap. is pressed to the inner peripheral side, it is wound and sealed by the diameter-reduced portion below the bulging portion.

特開２０１６－１９６３３２号公報JP 2016-196332 A

ところで、近年このようなボトル缶では、その缶本体を形成する金属材料の省資源化や材料製造の際の省エネルギー化のために缶本体の軽量化が求められており、例えば１缶当たり１ｇ軽量化できただけでも、膨大な数が市場に流通するボトル缶では大幅な省資源化や省エネルギー化、あるいは缶本体のコスト削減を図ることができる。ここで、このような缶本体の軽量化を図るには、缶本体に成形される金属板の元板厚を薄くすることによって胴部や肩部、キャップ取付部を薄肉化することが考えられる。 By the way, in recent years, in such bottle cans, there has been a demand for a lighter can body in order to conserve the resources of the metal material forming the can body and to save energy in the material manufacturing process. Even if it is possible to make it possible, it is possible to significantly save resources and energy, or to reduce the cost of the can itself, in the huge number of bottle cans on the market. Here, in order to reduce the weight of the can body, it is conceivable to reduce the original plate thickness of the metal plate formed into the can body, thereby thinning the body portion, the shoulder portion, and the cap attaching portion. .

しかしながら、そのような薄肉化したボトル缶において、特許文献１に記載されているように雄ネジ部の終端が膨出部に到達していると、膨出部が下方に向かって膨らむ拡径部の缶軸方向の長さが周方向に不均一となり、この雄ネジ部の終端近傍では拡径部が短くなって、拡径部の缶軸に沿った断面が該缶軸に対してなす傾斜角度が大きくなるため、缶軸方向の座屈強度を確保することができなくなって、キャッピングの際にキャップを絞り加工したときにキャップ取付部に局所的な座屈を生じるおそれがある。 However, in such a thin-walled bottle can, if the terminal end of the male threaded portion reaches the bulging portion as described in Patent Document 1, the bulging portion is an enlarged diameter portion that bulges downward. The length in the direction of the can axis becomes uneven in the circumferential direction, the enlarged diameter part becomes short near the terminal end of the male screw part, and the cross section of the enlarged diameter part along the can axis forms an inclination with respect to the can axis Since the angle becomes large, the buckling strength in the can axial direction cannot be ensured, and there is a possibility that local buckling may occur in the cap mounting portion when the cap is drawn during capping.

このような局所的な座屈が生じると、この座屈が生じた部分が起点となってスカートローラーによってキャップの開放端部を膨出部の縮径部に巻き締めする際の押圧力に抗しきれずに、雄ネジ部に変形を生じてしまう。そして、このように雄ネジ部が変形すると、一旦キャップをキャップ取付部から取り外した後に再び雄ネジ部にねじ込んで取り付ける際の回転トルク（リシールトルク）が増大したり、場合によってはキャップを取り付けることができなくなってリシールできなくなったりすることがある。 When such local buckling occurs, the portion where the buckling occurs becomes the starting point, and the skirt roller is used to wind the open end of the cap onto the reduced diameter portion of the bulging portion, thereby resisting the pressing force. It cannot be completely tightened, and deformation occurs in the male threaded portion. If the male threaded portion is deformed in this manner, the rotational torque (reseal torque) increases when the cap is once removed from the cap attachment portion and then screwed onto the male threaded portion to attach the cap. may not be able to reseal.

本発明は、このような背景の下になされたもので、薄肉化したボトル缶であっても、キャップ取付部の缶軸方向の座屈強度を確保することができて、リシールトルクが増大したり、リシールできなくなったりするのを防ぐことが可能なボトル缶を提供することを目的としている。 The present invention has been made under such a background, and is capable of securing the buckling strength of the cap attachment portion in the can axial direction even for a thin-walled bottle can, thereby increasing the resealing torque. To provide a bottle-can capable of preventing resealing from becoming impossible.

上記課題を解決して、このような目的を達成するために、本発明は、缶軸を中心とする有底筒状の缶本体の上端部に、キャップが取り付けられる円筒状のキャップ取付部が形成された金属製のボトル缶であって、上記キャップ取付部は、上端側に雄ネジ部を備えるとともに、下端側には下方に向かうに従い外周側に膨らんだ後に縮径して上記キャップの下端の開放端部が巻き締められる膨出部を備え、上記膨出部は、上記缶軸に沿った断面が該缶軸回りの全周に亙って同一で、上記雄ネジ部と上記缶軸方向に分けられており、上記膨出部は、上記缶軸に沿った断面において直線状に下方に向かうに従い外周側に膨らむ拡径部を上端側に備えるとともに、下端側には上記缶軸に沿った断面において直線状に下方に向かうに従い縮径する縮径部を備え、上記拡径部の上記缶軸に対する傾斜角は３°～３０°とされ、上記縮径部の上記缶軸に対する傾斜角が４０°～５０°とされ、上記雄ネジ部の下端は、上記膨出部に達することはなく、上記拡径部の上記缶軸方向の長さが上記缶軸回りの全周に亙って均一であるとともに、この拡径部が上記缶軸に沿った断面で上記缶軸に対してなす上記傾斜角も上記缶軸回りの全周に亙って一定であることを特徴とする。 In order to solve the above-mentioned problems and achieve such objects, the present invention provides a cylindrical cap attachment portion to which a cap is attached at the upper end of a bottomed cylindrical can body centered on the can axis. The cap attaching portion has a male threaded portion on the upper end side, and the cap attachment portion expands toward the outer peripheral side toward the lower end side and then reduces in diameter to form the lower end of the cap. The open end of the bulging portion has the same cross section along the can axis over the entire periphery of the can axis, and the male screw portion and the can axis The bulging portion has an enlarged diameter portion on the upper end side that swells toward the outer peripheral side as it goes linearly downward in a cross section along the can axis, and has an enlarged diameter portion on the lower end side that is aligned with the can axis. A diameter-reduced portion whose diameter decreases linearly downward in a cross-section along the length thereof, wherein the inclination angle of the enlarged-diameter portion with respect to the can axis is 3° to 30°, and the inclination of the diameter-reduced portion with respect to the can axis is set. The angle is 40° to 50°, the lower end of the male screw portion does not reach the bulging portion, and the length of the enlarged diameter portion in the can axis direction extends along the entire circumference of the can axis. In addition to being uniform over the can axis, the angle of inclination of the enlarged diameter portion with respect to the can axis in a cross section along the can axis is also constant over the entire circumference of the can axis. do.

このように構成されたボトル缶においては、キャップ取付部の雄ネジ部が膨出部に到達することなく膨出部と缶軸方向に分けられており、膨出部は缶軸に沿った断面が缶軸回りの全周に亙って同一であって、膨出部の下方に向かって膨らむ拡径部の缶軸方向の長さは均一であり、缶軸に沿った断面で拡径部が缶軸に対してなす傾斜角度も一定である。このため、膨出部の缶軸方向の座屈強度も缶軸回りの全周に亙って均一とすることができて、キャッピングの際の絞り加工の荷重によってキャップ取付部に局所的な座屈が生じるのを防ぐことができる。 In the bottle-shaped can configured in this way, the male threaded portion of the cap attachment portion is separated from the bulging portion in the can axial direction without reaching the bulging portion. is the same over the entire circumference of the can axis, and the length in the can axis direction of the enlarged diameter portion that bulges downward from the bulging portion is uniform. is also constant with respect to the can axis. For this reason, the buckling strength of the bulging portion in the direction of the can axis can be made uniform over the entire circumference of the can axis, and the load of the drawing process during capping causes local bearings on the cap mounting portion. You can prevent bending.

従って、スカートローラーによって押圧してキャップの開放端部を膨出部の縮径部に巻き締めする際に、このような局所的な座屈を起点として雄ネジ部に変形が生じるのも防ぐことができる。このため、このような雄ネジ部の変形によって一旦取り外したキャップをリシールできなくなるような事態が生じたりするのは勿論、リシールトルクが増大したりするのも防ぐことができ、リシール性を損なうことなく確実にボトル缶を薄肉化することが可能となる。 Therefore, when the open end of the cap is pressed by the skirt roller and wound around the diameter-reduced portion of the bulging portion, it is possible to prevent deformation of the male thread portion caused by such local buckling as a starting point. can be done. Therefore, it is possible to prevent the cap from being resealed once removed due to such deformation of the male screw portion, and to prevent an increase in the resealing torque, thereby impairing the resealing property. Therefore, it is possible to surely reduce the wall thickness of the bottle-can.

また、本発明では、上記膨出部は、上記缶軸に沿った断面において直線状に下方に向かうに従い外周側に膨らむ拡径部を上端側に備えている。このような角度範囲であれば、膨出部の座屈強度が一層向上する。なお、この拡径部の缶軸Ｃに対する傾斜角は５°～１５°であることがより好ましい。 Further, in the present invention, the bulging portion has, on the upper end side, an enlarged diameter portion that bulges toward the outer peripheral side in a straight line downward in a cross section along the can axis. With such an angle range, the buckling strength of the bulging portion is further improved. It is more preferable that the angle of inclination of the enlarged diameter portion with respect to the can axis C is 5° to 15°.

さらに、本発明では、上記膨出部の下端側に、缶軸に沿った断面において直線状に下方に向かうに従い縮径する縮径部を備えており、この縮径部の缶軸に対する傾斜角は４０°～５０°とされている。このような角度範囲であれば、キャップの開放端部を裾巻きするのに適している。Further, in the present invention, the lower end side of the bulging portion is provided with a diameter-reduced portion whose diameter decreases linearly downward in a cross-section along the can axis, and the inclination angle of the diameter-reduced portion with respect to the can axis. is 40° to 50°. Such an angular range is suitable for skirting the open end of the cap.

以上説明したように、本発明によれば、ボトル缶の薄肉化を図っても、キャッピングの際にキャップ取付部に局所的な座屈が生じるのを防ぐことができ、キャップの開放端部の巻締めによって雄ネジ部が変形するのを防止して、キャップのリシールトルクが増大したり、キャップがリシール不能となったりするのを防ぐことができる。 INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to prevent local buckling of the cap mounting portion during capping even when the thickness of the bottle can is reduced, and the open end portion of the cap can be prevented from buckling. It is possible to prevent deformation of the male threaded portion due to seaming, thereby preventing an increase in the resealing torque of the cap and an inability to reseal the cap.

本発明の実施形態を説明する上での第１の参考例を示す側面図である。It is a side view which shows the 1st reference example in describing embodiment of this invention. 図１に示す参考例のキャップ取付部の断面図である。FIG. 2 is a cross-sectional view of a cap mounting portion of the reference example shown in FIG. 1; 本発明の第２の参考例のキャップ取付部を示す側面図である。FIG. 11 is a side view showing a cap mounting portion of a second reference example of the present invention; 図３に示す参考例のキャップ取付部の断面図である。FIG. 4 is a cross-sectional view of the cap mounting portion of the reference example shown in FIG. 3; 本発明の第３の参考例を示す一部破断側面図である。It is a partially broken side view which shows the 3rd reference example of this invention. 本発明の第４の参考例のキャップ取付部を示す側面図である。FIG. 11 is a side view showing a cap mounting portion of a fourth reference example of the present invention;

図１および図２は、本発明の一実施形態を説明する上での第１の参考例を示すものである。本参考例のボトル缶において、その缶本体１は、底部２と、この底部２と一体に形成されて底部２の外周縁から上端側（図１および図２において上側）に延びる外周部３とを備えた缶軸Ｃを中心とする概略多段の有底円筒状をなしている。底部２には、缶軸Ｃ方向の内側（缶本体１の上端側）に凹む断面略円弧状のドーム部２ａが中央に形成されるとともに、このドーム部２ａの外周には缶軸Ｃ方向の外側（缶本体１の下端側）に突出する環状凸部２ｂが缶軸Ｃ回りの周方向に連続して形成されている(図５参照。）。 1 and 2 show a first reference example for describing one embodiment of the present invention. In the bottle can of this reference example , the can body 1 includes a bottom portion 2 and an outer peripheral portion 3 formed integrally with the bottom portion 2 and extending from the outer peripheral edge of the bottom portion 2 to the upper end side (upper side in FIGS. 1 and 2). It has a substantially multistage bottomed cylindrical shape centered on the can axis C. A dome portion 2a having a substantially arcuate cross-section is formed in the center of the bottom portion 2 and recessed inward in the direction of the can axis C (upper end side of the can body 1). An annular projection 2b protruding outward (lower end side of the can body 1) is continuously formed in the circumferential direction around the can axis C (see FIG. 5).

また、外周部３には底部２から缶本体１の上端側の開口部４に向けて順に、缶軸Ｃを中心とした円筒状の胴部５と、上端側に向かうに従い一定の傾斜で漸次縮径する円錐台面状の肩部６と、この肩部６からさらに上端側に向かって延びる筒状の首部７と、キャップ取付部８とが形成されている。このキャップ取付部８は、缶本体１を封止するキャップの雌ネジ部にねじ込まれる雄ネジ部９を上端側に備えるとともに、この雄ネジ部９よりも下端側には下方に向かうに従い外周側に膨らんだ後に縮径して上記キャップの下端の開放端部が巻き締められる膨出部１０を備えている。なお、キャップ取付部８の最上端部はカール部８ａとされている。 In addition, on the outer peripheral portion 3, a cylindrical body portion 5 centering on the can axis C is arranged in order from the bottom portion 2 toward the opening portion 4 on the upper end side of the can body 1, and gradually with a constant inclination toward the upper end side. A truncated conical shoulder portion 6 with a reduced diameter, a cylindrical neck portion 7 extending from the shoulder portion 6 toward the upper end, and a cap mounting portion 8 are formed. The cap mounting portion 8 has a male threaded portion 9 screwed into the female threaded portion of the cap that seals the can body 1 on the upper end side. It is provided with a bulging portion 10 which is swelled to a large extent and then reduced in diameter and wound around the open end portion of the lower end of the cap. The uppermost end of the cap attachment portion 8 is a curled portion 8a.

ここで、缶本体１の底部２の下端縁（環状凸部２ｂの下端縁）から外周部３の上端（カール部８ａの上端縁）までの缶高さは、内容物の容量が３１０ｍｌ用のボトル缶の缶本体１では１３１．６ｍｍ～１３３．６ｍｍ、内容物の容量が４１０ｍｌ用のボトル缶の缶本体１では１６３．０ｍｍ～１６５．０ｍｍとされる。また、缶本体１の外周部３における胴部５の直径は、ともに６４．２４ｍｍ～６８．２４ｍｍとされる。 Here, the can height from the lower edge of the bottom portion 2 of the can body 1 (the lower edge of the annular convex portion 2b) to the upper edge of the outer peripheral portion 3 (the upper edge of the curled portion 8a) is for a content capacity of 310 ml. The can body 1 of the bottle-can is 131.6 mm to 133.6 mm, and the can body 1 of the bottle-can for the content capacity of 410 ml is 163.0 mm to 165.0 mm. Also, the diameter of the body portion 5 in the outer peripheral portion 3 of the can body 1 is both 64.24 mm to 68.24 mm.

このようなボトル缶を製造するには、まずカッピングプレス機によるカッピングプレス工程において、金属板を円板状に打ち抜いて絞り加工を施すことにより深さの浅いカップ状素材を製造する。このカッピングプレス工程においてカップ状素材に成形される金属板は、３１０ｍｌ用のボトル缶の缶本体１では元板厚が０．２６０ｍｍ～０．３１０ｍｍ、４１０ｍｌ用のボトル缶の缶本体１では元板厚が０．３１０ｍｍ～０．３６５ｍｍのアルミニウム板またはＪＩＳＨ４０００におけるＡ３００４あるいはＡ３１０４のアルミニウム合金板であって、２０５℃×２０分ベーキング後の０．２％耐力が２３５Ｎ／ｍｍ^２～２６５Ｎ／ｍｍ^２の範囲のものが例えば用いられる。 In order to manufacture such bottle cans, first, in a cupping press step using a cupping press, a metal plate is punched into a disk shape and drawn to manufacture a shallow cup-shaped material. The metal plate formed into the cup-shaped material in this cupping press process has a base plate thickness of 0.260 mm to 0.310 mm for the can body 1 of the 310 ml bottle can, and a base plate thickness for the can body 1 of the 410 ml bottle can. An aluminum plate with a thickness of 0.310 mm to 0.365 mm or an aluminum alloy plate of A3004 or A3104 according to JIS H 4000, having a 0.2% proof stress of 235 N/mm ² to 265 N/mm after baking at 205°C for 20 minutes. A range of ² is used, for example.

次に、このカップ状素材にＤＩプレス機によるＤＩプレス工程において再絞りおよびしごき加工を施して缶軸Ｃ方向に延伸することにより、外周部に上記缶軸Ｃを中心とした円筒部が形成されるとともに、底部には缶本体１と同様のドーム部２ａと環状凸部２ｂが形成された有底円筒体を成形する。この有底円筒体および缶本体１の底部２の厚さは、カッピングプレス工程においてカップ状素材に成形される金属板の元板厚と略等しい。 Next, the cup-shaped material is subjected to redrawing and ironing in a DI press process using a DI press machine, and then stretched in the direction of the can axis C to form a cylindrical portion around the can axis C on the outer peripheral portion. At the same time, a bottomed cylindrical body having a dome portion 2a and an annular convex portion 2b similar to those of the can body 1 is formed at the bottom. The thickness of the bottomed cylindrical body and the bottom portion 2 of the can body 1 is substantially equal to the original plate thickness of the metal plate formed into the cup-shaped material in the cupping press process.

また、この有底円筒体の上記円筒部は、その外径（直径）が缶本体１の胴部５の外径と略等しい一定外径とされる。さらに、この円筒部の底部側の部分は厚さ（肉厚）が薄くされた薄肉部であるウォール部とされるとともに、底部とは反対の上端側の部分は、ウォール部よりも厚さが厚くされた厚肉部であるフランジ部とされている。ここで、このような厚さの異なるウォール部とフランジ部とを円筒部に形成するには、上述のようにＤＩプレス機において複数のしごきダイスとの間でしごき加工を行うパンチの外表面のフランジ部と対応する位置に、肉厚の差を考慮した深さの凹部を形成しておけばよい。 The cylindrical portion of the bottomed cylindrical body has a constant outer diameter (diameter) substantially equal to the outer diameter of the body portion 5 of the can body 1 . Furthermore, the portion on the bottom side of the cylindrical portion is a wall portion, which is a thin portion with a reduced thickness (thickness), and the portion on the upper end side opposite to the bottom portion is thicker than the wall portion. It is considered as a flange portion which is a thickened thick portion. Here, in order to form the wall portion and the flange portion having different thicknesses in the cylindrical portion, the outer surface of the punch which is subjected to ironing with a plurality of ironing dies in the DI press machine as described above must be A recess having a depth that takes account of the difference in thickness may be formed at a position corresponding to the flange.

また、このような有底円筒体においては、円筒部のウォール部のうち最薄部の厚さが０．１００ｍｍ～０．１３０ｍｍの範囲とされるとともに、円筒部のうち最も厚肉となるフランジ部の厚さが０．１６０ｍｍ～０．２１０ｍｍとされる。さらに、このフランジ部とウォール部のうち最薄部との間の段差は０．０９０ｍｍ以下となるようにされ、０．０７０ｍｍ以下とされるのが望ましく、ただし０．０４５ｍｍ以上であることが望ましい。 In such a bottomed cylindrical body, the thickness of the thinnest portion of the wall portion of the cylindrical portion is in the range of 0.100 mm to 0.130 mm, and the thickest portion of the cylindrical portion is the flange. The thickness of the portion is 0.160 mm to 0.210 mm. Furthermore, the step between the flange portion and the thinnest portion of the wall portion is 0.090 mm or less, preferably 0.070 mm or less, but preferably 0.045 mm or more. .

このように成形された有底円筒体は、トリマーによるトリミング工程において円筒部の上端縁が所定のトリム代で切断されて高さが揃えられてから、第１の洗浄工程において洗浄、乾燥され、次に塗装工程において内外面に塗装が施されて焼き付けられる。さらに、塗装が施された有底円筒体は、ボトルネッカーによるボトルネック成形工程において、円筒部のうちフランジ部の範囲が縮径されて上記肩部６と首部７が成形される。 In the trimming step using a trimmer, the cylindrical body with a bottom formed in this way is trimmed at the upper end edge of the cylindrical portion with a predetermined trim margin to align the height, and then washed and dried in the first washing step. Next, in the painting process, the inner and outer surfaces are painted and baked. Further, in the bottleneck molding process using a bottle necker, the diameter of the flange portion of the cylindrical portion of the painted bottomed cylindrical body is reduced, and the shoulder portion 6 and the neck portion 7 are formed.

次いで、首部７の上端側が拡径されて上記膨出部１０が形成されるとともに、この膨出部１０よりも上端側にはスレッディング加工によって上記雄ネジ部９が形成され、雄ネジ部９よりも上端側部分が外周側に折り返されてカールされてからスロットル加工によって潰されて上記カール部８ａとされることにより、キャップ取付部８が成形される。 Next, the upper end side of the neck portion 7 is enlarged to form the bulging portion 10, and the male screw portion 9 is formed on the upper end side of the bulging portion 10 by threading. The cap mounting portion 8 is formed by folding the upper end portion to the outer peripheral side, curling it, and then crushing it by throttle processing to form the curled portion 8a.

ここで、雄ネジ部９は、カール部８ａ側から平面視に時計回り方向に向かうに従い下端側に向かって捩れつつネジ山が不完全ネジ部において徐々に外周側に突出し、ネジ始まり部においてネジ山の左右の斜面が対称なネジとして有効に機能する完全ネジ部となる。さらに、雄ネジ部９は、この完全ネジ部においてネジ山が有効ネジ巻き数１巻以上（本実施形態では２．２巻）周回したところで内周側に徐々に後退して再び不完全ネジ部となる。このような雄ネジ部９の完全ネジ部におけるネジ谷の底からネジ山の頂点までのネジ高さは、例えば雄ネジ部９において最も外径の大きなネジ山のネジ谷部からネジ高さの５０％以上とされる。 Here, the male screw portion 9 is twisted toward the lower end side as it goes clockwise in plan view from the side of the curl portion 8a, and the screw thread gradually protrudes to the outer peripheral side at the incomplete screw portion. The left and right slopes of the crest form a complete screw portion that effectively functions as a symmetrical screw. Further, the male threaded portion 9 gradually retracts toward the inner peripheral side when the screw thread has made one or more effective screw turns (2.2 turns in this embodiment) in the complete threaded portion, and again the incompletely threaded portion. becomes. The screw height from the bottom of the screw root to the top of the screw thread in the fully threaded portion of the male screw portion 9 is, for example, the screw height from the screw root portion of the screw thread with the largest outer diameter in the male screw portion 9. 50% or more.

また、この第１の参考例では、上記膨出部１０は、缶軸Ｃに沿った断面において凸曲線を描きつつ下方に向かうに従い外周側に膨らむ拡径部１０ａを上端側に備えるとともに、下端側にはこの拡径部１０ａの断面がなす凸曲線に滑らかに連なる断面凸曲線状をなして下方に向かうに従い縮径する縮径部１０ｂを備えている。縮径部１０ｂの断面がなす凸曲線は拡径部１０ａがなす凸曲線よりも曲率半径が小さく、この縮径部１０ｂに上記キャップの開放端部が巻き締められる。そして、このような第１の参考例に対して、本発明の一実施形態では、拡径部１０ａは、缶軸Ｃに沿った断面において直線状に下方に向かうに従い外周側に膨らんでおり、その缶軸Ｃに対する傾斜角は３°～３０°とされていて、５°～１５°がより好ましい。このような角度範囲であれば、膨出部１０の座屈強度が一層向上する。また、縮径部１０ｂも、缶軸Ｃに沿った断面において直線状に下方に向かうに従い縮径しており、その缶軸Ｃに対する傾斜角は４０°～５０°とされている。このような角度範囲であれば、キャップの開放端部を裾巻きするのに適している。なお、この膨出部１０における拡径部１０ａと縮径部１０ｂとの境界、すなわち膨出部１０の最大外径の位置における該膨出部１０の缶軸Ｃに対する径方向の厚さｔは、上述のような元板厚が薄肉化された金属板から成形されるボトル缶においては０．１６５ｍｍ～０．２２０ｍｍの範囲とされる。 In the first reference example, the bulging portion 10 has an enlarged diameter portion 10a on the upper end side that bulges toward the outer peripheral side as it goes downward while drawing a convex curve in a cross section along the can axis C, and On the side thereof, there is provided a diameter-reduced portion 10b which has a convex curve shape in cross section smoothly connecting to the convex curve formed by the cross-section of the diameter-enlarged portion 10a and whose diameter decreases downward. The convex curve formed by the section of the reduced diameter portion 10b has a smaller radius of curvature than the convex curve formed by the enlarged diameter portion 10a, and the open end of the cap is wound around the reduced diameter portion 10b. In contrast to such a first reference example, in one embodiment of the present invention, the enlarged diameter portion 10a swells toward the outer peripheral side as it extends linearly downward in a cross section along the can axis C , The inclination angle with respect to the can axis C is 3° to 30°, more preferably 5° to 15°. With such an angle range, the buckling strength of the bulging portion 10 is further improved. The diameter-reduced portion 10b also linearly decreases in diameter downward in a cross section along the can axis C , and the inclination angle thereof with respect to the can axis C is set to 40° to 50°. Such an angular range is suitable for skirting the open end of the cap. The thickness t of the bulging portion 10 in the radial direction with respect to the can axis C at the boundary between the enlarged diameter portion 10a and the reduced diameter portion 10b of the bulging portion 10, that is, the position of the maximum outer diameter of the bulging portion 10 is In the case of a bottle-shaped can formed from a metal plate having a reduced original thickness as described above, the thickness is in the range of 0.165 mm to 0.220 mm.

そして、上記構成のボトル缶では、こうして成形された缶本体１の上記キャップ取付部８において、膨出部１０は、缶軸Ｃに沿った断面が缶軸Ｃ回りの全周に亙って同一で、雄ネジ部９と缶軸Ｃ方向に分けられている。すなわち、雄ネジ部９の終端（下端）は、膨出部１０に達することはなく、本実施形態では図１に示すように雄ネジ部９の上記終端におけるネジ山およびネジ谷と膨出部１０の拡径部１０ａとの間には缶軸Ｃ方向に間隔があけられている。 In the bottle can having the above structure, in the cap attachment portion 8 of the can body 1 formed in this manner, the bulging portion 10 has the same cross section along the can axis C over the entire circumference around the can axis C. , and is separated in the direction of the male screw portion 9 and the can axis C. That is, the terminal end (lower end) of the male threaded portion 9 does not reach the bulging portion 10, and in this embodiment, as shown in FIG. 10 is spaced in the can axis C direction from the enlarged diameter portion 10a.

このように構成されたボトル缶においては、キャップ取付部８の雄ネジ部９が膨出部１０に達することなく膨出部１０と缶軸Ｃ方向に分けられており、膨出部１０は缶軸Ｃに沿った断面が缶軸Ｃ回りの全周に亙って同一であるので、膨出部１０の下方に向かって膨らむ拡径部１０ａの缶軸Ｃ方向の長さも全周に亙って均一であるとともに、この拡径部１０ａが缶軸Ｃに沿った断面で缶軸Ｃに対してなす傾斜角度も一定であり、従って膨出部１０の缶軸Ｃ方向の座屈強度も缶軸Ｃ回りの全周に亙って均一とすることができる。 In the bottle-can constructed in this manner, the male screw portion 9 of the cap attachment portion 8 is separated from the bulging portion 10 in the direction of the can axis C without reaching the bulging portion 10, and the bulging portion 10 is separated from the can axis C direction. Since the cross section along the axis C is the same over the entire circumference around the can axis C, the length of the enlarged diameter portion 10a that bulges downward from the bulging portion 10 in the direction of the can axis C also extends over the entire circumference. In addition, the angle of inclination of the enlarged diameter portion 10a with respect to the can axis C in the cross section along the can axis C is also constant. It can be made uniform all around the circumference of the axis C.

このため、拡径部１０ａの長さや傾斜角度、座屈強度の不均一により、キャッピングの際の絞り加工の荷重によってキャップ取付部８に局所的な座屈が生じるのを防ぐことができ、スカートローラーによって押圧してキャップの開放端部を膨出部１０の縮径部１０ｂに巻き締めする際に、このような局所的な座屈を起点として雄ネジ部９に変形が生じるのを防ぐことができる。従って、上述のようにボトル缶の缶本体１を薄肉化しても、このような雄ネジ部９の変形によって一旦取り外したキャップをリシールできなくなるような事態が生じたり、リシールトルクが増大したりするのを防ぐことができ、確実にキャップをリシールすることが可能となる。 Therefore, it is possible to prevent local buckling of the cap mounting portion 8 due to the load of the drawing process during capping due to non-uniformity in the length, inclination angle, and buckling strength of the enlarged diameter portion 10a. To prevent deformation of the male screw portion 9 originating from such local buckling when the open end portion of the cap is pressed by a roller and wound around the reduced diameter portion 10b of the bulging portion 10. can be done. Therefore, even if the can body 1 of the bottle can is made thinner as described above, such deformation of the male screw portion 9 may cause a situation in which the once removed cap cannot be resealed, or the resealing torque may increase. can be prevented, and the cap can be reliably resealed.

また、本実施形態では、上述のように雄ネジ部９の終端におけるネジ山およびネジ谷と膨出部１０の拡径部１０ａとの間に缶軸Ｃ方向に間隔があけられており、これにより一層確実に雄ネジ部９が膨出部１０に到達して食い込むのを防ぐことができる。ただし本発明の参考例では、このように雄ネジ部９が膨出部１０に食い込むことがなければ、雄ネジ部９の終端におけるネジ山およびネジ谷と膨出部１０の拡径部１０ａとは接していてもよい。 Further, in the present embodiment, as described above, a space is provided in the can axis C direction between the screw thread and thread root at the terminal end of the male screw portion 9 and the enlarged diameter portion 10a of the bulging portion 10. Thus, it is possible to more reliably prevent the male screw portion 9 from reaching and biting into the bulging portion 10. - 特許庁However, in the reference example of the present invention , if the male screw portion 9 does not bite into the bulging portion 10 as described above, the screw thread and thread root at the terminal end of the male screw portion 9 and the enlarged diameter portion 10a of the bulging portion 10 may be in contact.

次に、図３および図４は、本発明の実施形態に対する第２の参考例を示すものであり、図１および図２に示した第１の参考例と共通する部分には同一の符号を配して説明を省略する。この第２の参考例においては、キャップ取付部８の雄ネジ部９と膨出部１０との間に、キャップ取付部８の内周側に凹む凹部１１が缶軸Ｃ回りの全周に亙って形成されていることを特徴とする。 Next, FIGS. 3 and 4 show a second reference example for the embodiment of the present invention, and parts common to the first reference example shown in FIGS. 1 and 2 are assigned the same reference numerals. , and the explanation is omitted. In this second reference example, a concave portion 11 recessed toward the inner peripheral side of the cap mounting portion 8 is formed along the entire circumference of the can axis C between the male screw portion 9 and the bulging portion 10 of the cap mounting portion 8. It is characterized by being formed as follows.

本参考例における凹部１１は、缶軸Ｃ方向において雄ネジ部９の終端から僅かに下端側に間隔をあけた位置から缶軸Ｃに沿った断面において凹曲線を描きつつ内周側に凹み始め、最も凹んだ位置を経た後に外周側に切れ上がって膨出部１０の拡径部１０ａに交差している。この凹部１１が缶軸Ｃに沿った断面においてなす凹曲線の曲率半径は、本参考例では拡径部１０ａの断面がなす凸曲線の曲率半径よりも大きくされている。 The recessed portion 11 in this reference example begins to dent inward while drawing a concave curve in a cross section along the can axis C from a position slightly spaced downward from the terminal end of the male screw portion 9 in the direction of the can axis C. , and after passing through the most recessed position, it rises to the outer peripheral side and intersects the enlarged diameter portion 10a of the bulging portion 10. - 特許庁The radius of curvature of the concave curve formed by the recess 11 in the cross section along the can axis C is made larger than the radius of curvature of the convex curve formed by the cross section of the enlarged diameter portion 10a in this reference example .

このように構成された第２の参考例では、この凹部１１によって雄ネジ部９と膨出部１０とをさらに確実に缶軸Ｃ方向に分けることができ、雄ネジ部９が膨出部１０に到達して食い込むのを防ぐことができる。また、こうして内周側に凹む凹部１１が全周に亙って形成されることにより、キャップ取付部８の缶軸Ｃ方向への荷重に対する座屈強度を一層向上させることができる。 In the second reference example configured as described above, the male threaded portion 9 and the bulging portion 10 can be more reliably separated in the direction of the can axis C by the recess 11, and the male threaded portion 9 is separated from the bulging portion 10 by the can axis C direction. can be prevented from reaching and eating into Further, by forming the concave portion 11 which is recessed toward the inner peripheral side in this manner over the entire circumference, the buckling strength of the cap attachment portion 8 against the load in the direction of the can axis C can be further improved.

さらに、図５および図６は、それぞれ本発明の実施形態に対する第３、第４の参考例を示すものであって、図１から図４に示した第１、第２の参考例と共通する部分にはやはり同一の符号を配して説明を省略する。これら第３、第４の参考例においては、上記第１、第２の参考例における雄ネジ部９の有効ネジ巻き数が２．２巻きであったのに対し、雄ネジ部９の有効ネジ巻き数が１．０巻き～１．７巻きの範囲（例えば１．５巻き）とされていることを特徴とする。なお、図５に示す第３の参考例では凹部１１がなく、図６に示す第４の参考例では雄ネジ部９と膨出部１０との間に凹部１１が形成されている。 Further, FIGS. 5 and 6 show third and fourth reference examples for the embodiment of the present invention, respectively, which are common to the first and second reference examples shown in FIGS. 1 to 4. The same reference numerals are assigned to the parts, and the description thereof is omitted. In these third and fourth reference examples, the number of effective screw turns of the male screw portion 9 was 2.2 turns in the first and second reference examples, whereas the number of effective screw turns of the male screw portion 9 was 2.2. The number of turns is in the range of 1.0 turns to 1.7 turns (for example, 1.5 turns). The third reference example shown in FIG. 5 does not have the concave portion 11, and the fourth reference example shown in FIG.

このような第３、第４の参考例では、有効ネジ巻き数が少ないので、雄ネジ部９の缶軸Ｃ方向の長さを短くすることができる。従って、キャップ取付部８や、このキャップ取付部８に取り付けられるキャップの缶軸Ｃ方向の長さも短くすることができるので、缶本体１の薄肉化と併せて、雄ネジ部９と膨出部１０とを缶軸Ｃ方向に分けても、確実にボトル缶やキャップ付きボトル缶の軽量化を促すことが可能となる。 In the third and fourth reference examples , since the number of effective screw turns is small, the length of the male screw portion 9 in the can axis C direction can be shortened. Therefore, the length of the cap attachment portion 8 and the length of the cap attached to the cap attachment portion 8 in the direction of the can axis C can be shortened. 10 can be divided in the can axis C direction, it is possible to surely promote weight reduction of bottle cans and bottle cans with caps.

１缶本体
２底部
３外周部
４開口部
５胴部
６肩部
７首部
８キャップ取付部
８ａカール部
９雄ネジ部
１０膨出部
１０ａ拡径部
１０ｂ縮径部
Ｃ缶軸 REFERENCE SIGNS LIST 1 can body 2 bottom 3 outer periphery 4 opening 5 trunk 6 shoulder 7 neck 8 cap mounting portion 8a curl portion 9 male screw portion 10 bulging portion 10a expanded diameter portion 10b reduced diameter portion C can shaft

Claims

A metal bottle can having a cylindrical cap attachment portion to which a cap is attached is formed at the upper end of a bottomed cylindrical can body centered on the can axis,
The cap mounting portion has a male threaded portion on the upper end side, and a bulging portion on the lower end side, which bulges to the outer peripheral side as it goes downward and then reduces in diameter so that the open end portion of the lower end of the cap is wound. prepared,
The bulging portion has the same cross section along the can axis over the entire circumference around the can axis, and is separated from the male screw portion in the can axis direction,
The bulging portion has an enlarged diameter portion on the upper end side that swells toward the outer peripheral side as it goes linearly downward in a cross section along the can axis, and has a linear shape on the lower end side in a cross section along the can axis. Equipped with a reduced diameter portion that decreases in diameter as it goes downward,
The inclination angle of the enlarged diameter portion with respect to the can axis is 3° to 30°, and the inclination angle of the diameter reduction portion with respect to the can axis is 40° to 50°,
The lower end of the male screw portion does not reach the bulging portion,
The length of the enlarged diameter portion in the can axis direction is uniform over the entire circumference around the can axis, and the enlarged diameter portion forms the can axis in a cross section along the can axis. A bottle can characterized in that the inclination angle is also constant over the entire periphery of the can axis .

2. The bottle can according to claim 1, wherein said enlarged diameter portion has an inclination angle of 5° to 15° with respect to said can axis.

A thickness of the bulging portion in a radial direction with respect to the can axis of the bulging portion at a boundary between the enlarged diameter portion and the reduced diameter portion is in the range of 0.165 mm to 0.220 mm. The bottle can according to claim 1 or claim 2.