JP3582224B2

JP3582224B2 - Bulge can manufacturing method

Info

Publication number: JP3582224B2
Application number: JP09366696A
Authority: JP
Inventors: 孝之相川; 守柴坂; 直森下
Original assignee: Toyo Seikan Kaisha Ltd
Current assignee: Toyo Seikan Kaisha Ltd
Priority date: 1996-03-22
Filing date: 1996-03-22
Publication date: 2004-10-27
Anticipated expiration: 2016-03-22
Also published as: JPH09253763A

Description

【０００１】
【発明の属する技術分野】
この発明はバルジ缶の製造方法に関するものである。
【０００２】
ビール、炭酸飲料、果汁飲料、コーヒー飲料等を充填する金属缶は、胴部が軸方向全体が同一径を有する円筒状の金属缶の他に、外観デザイン上の要請から、図１に示すような胴部２に膨出部３を形成したバルジ缶１が使用される。
【０００３】
【従来の技術】
バルジ缶１を製造する方法としては、図４に示すように、アルミ板、ブリキ板あるいはティンフリースチール板からなるブランクを、絞り−しごき成形、絞り−再絞り成形、絞り−薄肉化再絞り成形、絞り−薄肉化再絞り−しごき成形等に付して素缶４に成形し、次いで前記素缶４をリフター１０によってダイ５のキャビティー６内にセットし（図４ａ）、次いで前記素缶４の円筒形状の胴部２内に弾性ポンチ１２を挿入した後、前記弾性ポンチ１２にバルジ加工圧力Ｐを加えてバルジ成形を行い、前記キャビティー６の形状に対応する形状を前記素缶４の胴部２に成形することが一般に行われている。
【０００４】
【発明が解決しようとする課題】
しかしながらバルジ成形においては、素缶４の胴部２がバルジ成形時の径方向の伸びが良好でないと前記胴部２がバルジ成形時に破胴し、希望する外観形状が得られない。
【０００５】
素缶４の胴部２の径に対するバルジ缶１の胴部２の径方向の膨出率は、薄錫メッキ鋼板からなる溶接缶では１４％であるが、３０００系のアルミからなる絞り−しごき缶（アニーリング無し）では２％、ティンフリースチール板からなる絞り−薄肉化再絞り成形缶では１％程度ある。
【０００６】
このように、特に前記した絞り−しごき成形缶あるいは絞り−薄肉化再絞り成形缶等の缶胴側面に縦目（サイドシーム）を有しない２ピース缶（シームレス缶）は、素缶４の胴部２が前記成形によって加工硬化し、前記胴部２の径方向の伸び率（膨出率）が低下し、バルジ成形時に破胴を生じ易く、成形が困難となる。
【０００７】
このような径方向の伸び率が低下した絞り−しごき缶に対して、バルジ成形時に図４に示す様に、素缶４の上端部に軸方向力Ｆを加えることが知られているが、前記軸方向力Ｆは、素缶４の座屈強度以下に制限されてしまう。
【０００８】
本発明は上記事情に鑑みてなされたものであって、素缶に、素缶の座屈強度以上の軸方向力をバルジ加工の際に加えることを可能とし、これによって素缶の胴部の径方向のバルジ加工性を飛躍的に向上させ、胴部に破胴を生じることなく容易に製造可能で、しかも優れたデザインのバルジ缶を得るための製造方法を提供することを目的とするものである。
【０００９】
【課題を解決するための手段】
この目的に対応して本発明のバルジ缶の製造方法は、素缶から胴部に膨出部を有するバルジ缶を製造する方法において、素缶の胴部の膨出部以外の外面がダイに密着した状態に前記素缶をダイのキャビティー内に挿入し、前記素缶内に前記素缶の内径よりも小さな外径の薄膜弾性部材または弾性ポンチを挿入し、前記薄膜弾性部材または弾性ポンチによってバルジ加工圧力よりも小さい初期圧力を前記素缶に作用させかつ前記素缶に前記薄膜弾性部材または弾性ポンチを密着させた状態で前記素缶の上端を押圧する押圧リングによって前記素缶の座屈強度よりも大きい軸方向力を加えた後、前記軸方向力を加えた状態で前記薄膜弾性部材または弾性ポンチによってバルジ加工圧力を加えて胴部に膨出部を形成することを特徴としている。
【００１０】
【実施例】
以下、本発明の製造方法について図面に基づいて説明する。
【００１１】
図１はバルジ缶１の縦断面図で、胴部２にバルジ加工によって希望する外観形状の膨出部３が形成されている。
【００１２】
図２は本発明のバルジ缶の製造方法の第１実施例で、ダイ５は図示しないが二つの割型で、バルジ缶１の膨出部３の形状に対応した内面形状のキャビティー６を有する。
【００１３】
図中７は押圧リングで、ダイ５と同様二つの割型で、ダイ５にロッド８を介して取り付けられており、バルジ成形直前及びバルジ成形中に素缶４の上端部を押圧する。
【００１４】
また図中９は厚さ２ｍｍ程度のゴム等の薄膜弾性部材で、適宜手段で水等の流体を供給し、流体圧力によって膨張させるが、膨張前は素缶４の内径及び押圧リング７の内径よりも小さい外径を有する。
【００１５】
また図中１０はリフターで、素缶４をダイ５に挿入する際あるいは取り出す際に、前記素缶４をリフター１０上に固定するバキューム孔１１を有する。
【００１６】
図２（ａ）に示す様に、絞り−しごき成形によって形成された素缶４をリフター１０のバキューム孔１１の真空保持によって、ダイ５のキャビティー６内に供給した後、素缶４内に薄膜弾性部材９を挿入する。
【００１７】
次に図２（ｂ）に示す様に、薄膜弾性部材９を流体圧力によって膨張させ、素缶４の内面に前記薄膜弾性部材９を密着させて初期圧力Ｐ１を加える。またこの時、素缶４の胴部は図２に示すように、膨出部３以外の外面をダイに密着している。
【００１８】
この初期圧力Ｐ１を加えた状態で、図２（ｃ）に示す様に押圧リング７を下降させ、素缶４の上端部に前記素缶４の座屈強度よりも大きい下向きの軸方向力Ｆ１を加える。この時、図２に示すように、素缶４の胴部は図２に示すように、膨出部３以外の外面はダイに密着している。
【００１９】
この軸方向力Ｆ１を加えた状態で、図２（ｄ）に示す様に、素缶４に前記初期圧力Ｐ１よりも大きいバルジ加工圧力Ｐ２を加えて、前記素缶４の胴部２に膨出部３を形成しバルジ缶１を製造する。
【００２０】
そして図示しないが、押圧リング７を上方に移動して軸方向力Ｆ１を除去し、その後バルジ加工圧Ｐ２を除去し、薄膜弾性部材９を収縮してバルジ缶１内から取り出し、ダイ５を開いてキャビティー６内からリフター１０のバキューム孔１１の真空保持によって前記バルジ缶１を取り出す。
【００２１】
図３は本発明のバルジ缶の製造方法の第２実施例で、前記した第１実施例と同様に、バルジ缶１の膨出部３の形状に対応した内面形状のダイキャビティー６を設けたダイ５と素缶４の上端部を押圧する押圧リング７、素缶４を前記ダイキャビティー６内に供給するリフター１０を有する。
【００２２】
また図中１２はウレタン系ゴム等の弾性ポンチで、適宜手段で軸方向に圧縮して径方向に膨出させるが、膨出前は素缶４の内径及び押圧リング７の内径よりも小さい外径を有する。
【００２３】
バルジ成形に際しては図３（ａ）に示す様に、絞り−しごき成形によって成形された素缶４をリフター１０のバキューム孔１１の真空保持によってダイ５のキャビティー６内に供給した後、前記素缶４内に弾性ポンチ１２を挿入する。
【００２４】
次に、弾性ポンチ１２を軸方向圧力を加えて径方向に膨出させ、前記素缶４の内面に前記弾性ポンチ１２を密着させて初期圧力Ｐ１を加える。
【００２５】
この初期圧力Ｐ１を加えた状態で図３（ｂ）に示す様に、前記素缶４の座屈強度よりも大きい下向きの軸方向力Ｆ１を押圧リング７によって素缶４の上端部に加える。
【００２６】
この軸方向力Ｆ１を加えた状態で図３（ｃ）に示す様に、素缶４に前記初期圧力Ｐ１よりも大きいバルジ加工圧力Ｐ２を加えて、素缶４の胴部２に膨出部３を形成しバルジ缶１を製造する。
【００２７】
そして図示しないが、押圧リング７を上方に移動して軸方向力Ｆ１を除去し、その後バルジ加工圧Ｐ２を除去し、弾性ポンチ１２を収縮してバルジ缶１内から取り出し、ダイ５を開いてキャビティー６内からリフター１０のバキューム孔１１の真空保持によって前記バルジ缶１を取り出す。
【００２８】
なお本発明において、素缶４は前記した実施例に限定されることなく、絞り−再絞り成形缶、絞り−薄肉化再絞り成形缶、絞り−薄肉化再絞り−しごき成形缶等の缶胴側面に縦目（サイドシーム）を有しない２ピース缶（シームレス缶）、あるいは、溶接缶等の缶胴側面に継目を有するピース缶のいずれも用いることができる。
【００２９】
また本発明において、素缶４の上端部に加える軸方向力Ｆ１の方向は前記した実施例に限定されることなく、押圧リング７を固定した状態で素缶４をリフター１０によって下方から押し上げて、前記素缶４の上端部を押圧リング７に当接させても良い。
【００３０】
また本発明においては、前記軸方向力Ｆ１を加える時期は前記実施例に限定されず、初期圧力Ｐ１とほぼ同時に加えても良いが、耐座屈性の点から前記初期圧力Ｐ１を先行して加えるのが望ましい。
【００３１】
【発明の効果】
以上の説明から明らかな様に、本発明のバルジ加工缶の製造方法によれば、バルジ加工前に素缶のバルジ加工圧力よりも小さい初期圧力を加えることによってバルジ加工時に前記素缶に座屈強度以上の軸方向力を加えることができ、素缶の胴部の径方向のバルジ加工性を飛躍的に向上させ、胴部に破胴を生じることなく容易に製造可能となり、しかも優れたデザインのバルジ缶を得ることができる。
【図面の簡単な説明】
【図１】バルジ缶を示す縦断面説明図。
【図２】本発明の製造方法の第１実施例を示す説明図。
【図３】本発明の製造方法の第２実施例を示す説明図。
【図４】従来のバルジ缶の製造方法を示す説明図。
【符号の説明】
１バルジ缶
２胴部
３膨出部
４素缶
５ダイ
６キャビティー
７押圧リング
８ロッド
９薄膜弾性部材
１０リフター
１１バキューム孔
１２弾性ポンチ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a bulge can.
[0002]
Metal cans for filling beer, carbonated drinks, fruit drinks, coffee drinks, etc. are shown in FIG. A bulge can 1 having a bulging portion 3 formed on a simple body 2 is used.
[0003]
[Prior art]
As a method of manufacturing the bulge can 1, as shown in FIG. 4, a blank made of an aluminum plate, a tin plate or a tin-free steel plate is drawn-ironed, drawn-redrawn, drawn-thinned and redrawn. , Drawing, thinning, redrawing, ironing, etc. to form the raw can 4, and then setting the raw can 4 in the cavity 6 of the die 5 by the lifter 10 (FIG. 4 a) After the elastic punch 12 is inserted into the cylindrical body 2 of FIG. 4, a bulge forming pressure P is applied to the elastic punch 12 to form a bulge, and a shape corresponding to the shape of the cavity 6 is formed into the raw can 4. Is generally performed.
[0004]
[Problems to be solved by the invention]
However, in the bulge forming, if the body portion 2 of the raw can 4 is not good in elongation in the radial direction at the time of the bulge forming, the body portion 2 is broken at the time of the bulge forming, and a desired external shape cannot be obtained.
[0005]
The radial expansion ratio of the body portion 2 of the bulge can 1 to the diameter of the body portion 2 of the raw can 4 is 14% in a welding can made of thin tin plated steel sheet, but is drawn and ironed by 3000 series aluminum. The ratio is about 2% for cans (without annealing), and about 1% for draw-thinning redrawing cans made of tin-free steel plates.
[0006]
As described above, in particular, the two-piece can (seamless can) having no side eyes (side seam) on the side of the can body, such as the above-described drawn-ironed can or drawn-thinned re-drawn can, is used as the body of the raw can 4. The portion 2 is work-hardened by the molding, the radial elongation (bulging ratio) of the body 2 is reduced, and the bulge is likely to be broken at the time of bulge molding, making molding difficult.
[0007]
It is known that an axial force F is applied to the upper end portion of the raw can 4 as shown in FIG. 4 at the time of bulge forming on the drawn-ironed can having the reduced radial elongation, The axial force F is limited to the buckling strength of the raw can 4 or less.
[0008]
The present invention has been made in view of the above circumstances, and makes it possible to apply an axial force greater than the buckling strength of the raw can to the raw can at the time of bulging, thereby enabling the body of the raw can to be It is an object of the present invention to provide a manufacturing method for obtaining a bulge can of a superior design, which can dramatically improve radial bulge workability, can be easily manufactured without a broken body in the body, and has an excellent design. It is.
[0009]
[Means for Solving the Problems]
Method for producing a bulge can of the present invention in correspondence with this purpose, a method of producing a bulge can having a bulge portion in the body portion from Motokan, the die outer surface of the non-bulged portion of the body portion of Motokan The elemental can is inserted into the cavity of the die in a state of being in close contact, a thin film elastic member or an elastic punch having an outer diameter smaller than the inner diameter of the elemental can is inserted into the elemental can, and the thin film elastic member or the elastic punch is inserted. The initial pressure lower than the bulging pressure is applied to the raw can, and the thin-film elastic member or the elastic punch is brought into close contact with the raw can. After applying an axial force greater than the flexural strength, a bulging pressure is applied by the thin film elastic member or the elastic punch in a state where the axial force is applied to form a bulging portion on the body. .
[0010]
【Example】
Hereinafter, the manufacturing method of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a longitudinal sectional view of a bulge can 1, in which a bulge 3 having a desired external shape is formed on a body 2 by bulging.
[0012]
FIG. 2 shows a first embodiment of a method for manufacturing a bulge can according to the present invention. The die 5 is a split mold (not shown) and has a cavity 6 having an inner surface shape corresponding to the shape of the bulging portion 3 of the bulge can 1. Have.
[0013]
In the drawing, reference numeral 7 denotes a pressing ring, which is a split mold similar to the die 5 and is attached to the die 5 via a rod 8, and presses the upper end of the raw can 4 immediately before and during bulge forming.
[0014]
In the figure, reference numeral 9 denotes a thin film elastic member made of rubber or the like having a thickness of about 2 mm, which is supplied with a fluid such as water by an appropriate means and is expanded by the fluid pressure. It has a smaller outer diameter.
[0015]
In the figure, reference numeral 10 denotes a lifter, which has a vacuum hole 11 for fixing the raw can 4 on the lifter 10 when inserting or removing the raw can 4 from the die 5.
[0016]
As shown in FIG. 2A, the raw can 4 formed by drawing and ironing is supplied into the cavity 6 of the die 5 by holding the vacuum hole 11 of the lifter 10 in a vacuum. The thin film elastic member 9 is inserted.
[0017]
Next, as shown in FIG. 2B, the thin film elastic member 9 is expanded by a fluid pressure, and the thin film elastic member 9 is brought into close contact with the inner surface of the raw can 4, and an initial pressure P1 is applied. At this time, as shown in FIG. 2, the body of the raw can 4 has the outer surface other than the bulging portion 3 in close contact with the die.
[0018]
With this initial pressure P1 applied, the pressing ring 7 is lowered as shown in FIG. 2C, and a downward axial force F1 larger than the buckling strength of the raw can 4 is applied to the upper end of the raw can 4. Add. At this time, as shown in FIG. 2, the outer surface of the body of the raw can 4 other than the bulging portion 3 is in close contact with the die as shown in FIG.
[0019]
In a state where the axial force F1 is applied, as shown in FIG. 2D, a bulge processing pressure P2 larger than the initial pressure P1 is applied to the raw can 4 to expand the body 2 of the raw can 4. The protrusion 3 is formed to manufacture the bulge can 1 .
[0020]
Then, although not shown, the pressing ring 7 is moved upward to remove the axial force F1, then the bulging pressure P2 is removed, the thin film elastic member 9 is contracted and taken out of the bulge can 1, and the die 5 is opened. The bulge can 1 is taken out of the cavity 6 by holding the vacuum hole 11 of the lifter 10 in a vacuum.
[0021]
FIG. 3 shows a second embodiment of the method for manufacturing a bulge can according to the present invention. As in the first embodiment, a die cavity 6 having an inner surface shape corresponding to the shape of the bulging portion 3 of the bulge can 1 is provided. The die 5 has a pressing ring 7 for pressing the upper end of the raw can 4, and a lifter 10 for feeding the raw can 4 into the die cavity 6.
[0022]
In the figure, reference numeral 12 denotes an elastic punch made of urethane rubber or the like, which is compressed in the axial direction by appropriate means to expand in the radial direction, but before expansion, the outer diameter is smaller than the inner diameter of the raw can 4 and the inner diameter of the pressing ring 7. Having.
[0023]
At the time of bulge forming, as shown in FIG. 3 (a), the raw can 4 formed by draw-ironing is supplied into the cavity 6 of the die 5 by holding the vacuum hole 11 of the lifter 10 in a vacuum. The elastic punch 12 is inserted into the can 4.
[0024]
Next, the elastic punch 12 is swelled in the radial direction by applying an axial pressure, and the elastic punch 12 is brought into close contact with the inner surface of the raw can 4 to apply an initial pressure P1.
[0025]
With this initial pressure P1 applied, a downward axial force F1 larger than the buckling strength of the raw can 4 is applied to the upper end of the raw can 4 by the pressing ring 7, as shown in FIG.
[0026]
In a state where the axial force F1 is applied, as shown in FIG. 3 (c), a bulge processing pressure P2 larger than the initial pressure P1 is applied to the raw can 4, and the bulging portion is formed on the body 2 of the raw can 4. 3 and the bulge can 1 is manufactured.
[0027]
Then, although not shown, the pressing ring 7 is moved upward to remove the axial force F1, then the bulging pressure P2 is removed, the elastic punch 12 is contracted and taken out of the bulge can 1, and the die 5 is opened. The bulge can 1 is taken out of the cavity 6 by holding the vacuum hole 11 of the lifter 10 in a vacuum.
[0028]
In the present invention, the raw can 4 is not limited to the above-described embodiment, but can be a can body such as a draw-redrawing can, a draw-thinning redrawing can, or a draw-thinning redrawing-ironing can. Either a two-piece can (seamless can) having no vertical seam (side seam) on the side surface or a piece can having a seam on the side of the can body such as a welding can can be used.
[0029]
Further, in the present invention, the direction of the axial force F1 applied to the upper end of the raw can 4 is not limited to the above-described embodiment, and the raw can 4 is pushed up from below by the lifter 10 with the pressing ring 7 fixed. Alternatively, the upper end of the raw can 4 may be brought into contact with the pressing ring 7.
[0030]
Further, in the present invention, the timing of applying the axial force F1 is not limited to the above embodiment, and may be applied almost simultaneously with the initial pressure P1, but from the viewpoint of buckling resistance, the initial pressure P1 is preceded. It is desirable to add.
[0031]
【The invention's effect】
As is apparent from the above description, according to the bulging can manufacturing method of the present invention, the initial pressure smaller than the bulging pressure of the raw can is applied before bulging to buckle the raw can at the time of bulging. Able to apply axial force of strength or more, dramatically improving the radial bulge workability of the body of the raw can, making it easy to manufacture without breaking the body, and excellent design Bulge cans.
[Brief description of the drawings]
FIG. 1 is an explanatory longitudinal sectional view showing a bulge can.
FIG. 2 is an explanatory view showing a first embodiment of the manufacturing method of the present invention.
FIG. 3 is an explanatory view showing a second embodiment of the manufacturing method of the present invention.
FIG. 4 is an explanatory view showing a conventional method for manufacturing a bulge can.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 bulge can 2 trunk 3 bulge 4 raw can 5 die 6 cavity 7 press ring 8 rod 9 thin film elastic member 10 lifter 11 vacuum hole 12 elastic punch

Claims

素缶から胴部に膨出部を有するバルジ缶を製造する方法において、素缶の胴部の膨出部以外の外面がダイに密着した状態に前記素缶をダイのキャビティー内に挿入し、前記素缶内に前記素缶の内径よりも小さな外径の薄膜弾性部材または弾性ポンチを挿入し、前記薄膜弾性部材または弾性ポンチによってバルジ加工圧力よりも小さい初期圧力を前記素缶に作用させかつ前記素缶に前記薄膜弾性部材または弾性ポンチを密着させた状態で前記素缶の上端を押圧する押圧リングによって前記素缶の座屈強度よりも大きい軸方向力を加えた後、前記軸方向力を加えた状態で前記薄膜弾性部材または弾性ポンチによってバルジ加工圧力を加えて胴部に膨出部を形成することを特徴とするバルジ缶の製造方法。In a method of manufacturing a bulge can having a bulge in a body from a raw can , the raw can is inserted into a die cavity in a state in which the outer surface of the body of the raw can other than the bulge is in close contact with the die. A thin film elastic member or an elastic punch having an outer diameter smaller than the inner diameter of the raw can is inserted into the raw can, and an initial pressure smaller than a bulging pressure is applied to the raw can by the thin film elastic member or the elastic punch. And after applying an axial force larger than the buckling strength of the raw can by a pressing ring pressing the upper end of the raw can with the thin film elastic member or elastic punch adhered to the raw can, the axial direction A method for producing a bulge can, characterized in that a bulge processing pressure is applied by the thin film elastic member or the elastic punch in a state where a force is applied to form a bulge portion in the body.

バルジ加工圧力よりも小さい初期圧力を、薄膜弾性部材内に流体圧力を加えて得ることを特徴とする請求項１記載のバルジ缶の製造方法。2. The method for manufacturing a bulge can according to claim 1, wherein an initial pressure smaller than the bulge working pressure is obtained by applying a fluid pressure inside the thin film elastic member.

バルジ加工圧力よりも小さい初期圧力を、弾性ポンチに軸方向圧力を加えて得ることを特徴とする請求項１記載のバルジ缶の製造方法。2. The method for manufacturing a bulge can according to claim 1, wherein an initial pressure smaller than the bulge working pressure is obtained by applying an axial pressure to the elastic punch.