JP5359438B2

JP5359438B2 - Can body

Info

Publication number: JP5359438B2
Application number: JP2009073273A
Authority: JP
Inventors: 克己小島; 雅毅多田; 浩樹岩佐
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2009-03-25
Filing date: 2009-03-25
Publication date: 2013-12-04
Anticipated expiration: 2029-03-25
Also published as: JP2010222045A

Abstract

<P>PROBLEM TO BE SOLVED: To provide a can body having a high panelling strength and a high axial buckling strength. <P>SOLUTION: More than one portions of a cylindrical can body 1 have annular ribs 2 protruded along the entire periphery of the can body 1, wherein the annular ribs 2 have a structure in which a part of the cylindrical can body 1 is folded back and overlapped in an axial direction of the cylindrical can body and the protruding length (a) of the annular ribs 2 from the surface of the cylindrical can body is 1 mm or above. Since this structure is made such that the annular ribs 2 increase a panelling strength of the cylindrical can body 1 and the can body portion constituting the annular ribs 2 is folded back and overlapped in an axial direction of the cylindrical can body to form a closed structure, no buckling occurs against a load applied from this overlapped portion in the axial direction of the cylindrical can body. Due to this fact, it is possible to provide a cylindrical can body having a high panelling strength and a high axial buckling strength. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、飲料缶詰、食品缶詰などに好適な金属缶体に関するものである。 The present invention relates to a metal can suitable for canned beverages, canned foods and the like.

金属缶は、製造コスト低減の観点から、金属素材の使用量を低減する試みが進められている。そのための方法として、３ピース缶では、金属素材の板厚を薄くするゲージダウンが進められており、また、２ピース缶では、ゲージダウンとともに、缶胴をしごき加工などで薄肉化する方法が推進されている。しかし、こうしたゲージダウンや薄肉化を行うことで、缶体に必要な強度が低下するため、缶体強度の低下を缶胴の構造によって補うための検討が行われている。 For metal cans, attempts are being made to reduce the amount of metal materials used from the viewpoint of manufacturing cost reduction. As a method for this, in 3 piece cans, the gauge down to reduce the thickness of the metal material is being promoted, and in the 2 piece cans, along with the gauge down, the can body is thinned by ironing etc. Has been. However, since the strength required for the can body is reduced by performing such gauge down and thinning, studies have been made to compensate for the reduction in the strength of the can body by the structure of the can body.

特許文献１では、極薄溶接缶胴を有する３ピース缶について、複数本のビードを設けることにより、缶胴の耐圧強度を実用的な強度にまで補強するとともに、缶胴に施される印刷文字や印刷図柄のビードによる歪みを回避して、そのような歪みに起因する装飾効果の減殺や文字の読み難さを解消する技術を提案している。この技術では、板厚が０．１２〜０．１６ｍｍの表面処理鋼板から形成され、側面継目部が抵抗シーム溶接法により接合されている極薄溶接缶胴に対して、その缶胴の中央部で、缶胴の上下両端に缶蓋を巻締めた状態の缶の高さの２〜１５％の寸法の高さ方向の成形範囲巾内に、深さが０．１〜１．０ｍｍで、ピッチが２〜１０ｍｍのビードを複数本形成するものである。 In Patent Document 1, for a three-piece can having an ultra-thin welded can body, by providing a plurality of beads, the pressure resistance of the can body is reinforced to a practical strength, and printed characters are applied to the can body. And a technique for avoiding the distortion caused by the bead of the printed pattern and eliminating the decoration effect caused by such distortion and the difficulty of reading the characters. In this technique, a central portion of the can body is formed with respect to an ultra-thin welded can body formed of a surface-treated steel plate having a thickness of 0.12 to 0.16 mm and a side seam portion joined by a resistance seam welding method. Then, the depth is 0.1 to 1.0 mm within the molding range width in the height direction of the dimension of 2 to 15% of the height of the can in the state where the can lid is wound around the upper and lower ends of the can body, A plurality of beads having a pitch of 2 to 10 mm are formed.

特許文献２では、缶胴と缶底が一体的に形成された２ピース缶用の缶体について、軽量缶とするためにその缶胴を全体的に薄肉化しても、薄肉化された缶胴のパネル強度（耐バキューム性）と座屈強度をバランス良く強化することにより、陰圧缶詰としても充分に使用できる技術を提案している。この技術は、缶胴と缶底が一体的に形成された２ピース缶用の缶体において、缶体の上端近傍に形成される通常のネック部を除く缶胴の適所に、補強用の屈曲部分を缶胴の円周方向に沿って略環状に形成するとともに、この補強用の屈曲部分の板厚を、全体的に薄肉化された缶胴において他の部分（薄肉部分）よりも厚肉（厚肉部分）となるように形成するものである。 In Patent Document 2, even if the can body for a two-piece can, in which the can body and the bottom of the can are integrally formed, is thinned to make it a lightweight can, the thinned can body We are proposing a technology that can be used as a negative pressure canned product by strengthening the panel strength (vacuum resistance) and buckling strength in a well-balanced manner. In this technology, a can body for a two-piece can in which the can body and the bottom of the can are integrally formed is bent for reinforcement at an appropriate position of the can body except for a normal neck portion formed near the upper end of the can body. The part is formed in a substantially ring shape along the circumferential direction of the can body, and the thickness of the reinforcing bent portion is thicker than the other parts (thin parts) in the overall thinned can body It is formed so as to be (thick part).

特開２０００−７２１４３号公報JP 2000-72143 A 特開２００１−３３５０１８号公報JP 2001-335018 A

特許文献１では、缶内圧が負圧になる缶詰の場合に、缶胴が外圧によって凹まされる、いわゆるパネリング現象を回避することができるとしている。しかし、缶蓋を巻締固着するなどの際に缶胴に上方（軸線方向）から外力が加えられることで、缶胴が軸線方向に押し潰されて座屈する現象である軸座屈に対し、特許文献１で用いられているようなビード構造は、却ってその強度を低下させることが知られている。つまり、特許文献１の技術ではパネリング現象を回避することはできても、軸座屈現象を同時に回避することは困難である。
特許文献２では、パネリング現象および軸座屈現象の両者に対して効果があるとしている。しかし、特許文献２の技術は、缶胴に対して部分的に他の部分よりも厚い部分を設ける必要があり、３ピース缶への適用は不可能である。 In Patent Document 1, in the case of canning in which the internal pressure of the can is negative, a so-called paneling phenomenon in which the can body is recessed by external pressure can be avoided. However, when the can lid is tightly clamped, external force is applied to the can body from above (in the axial direction), so that the can body is crushed in the axial direction and buckled. It is known that the bead structure used in Patent Document 1 decreases its strength. In other words, even though the technique of Patent Document 1 can avoid the paneling phenomenon, it is difficult to avoid the axial buckling phenomenon at the same time.
In Patent Document 2, it is said that it is effective against both the paneling phenomenon and the shaft buckling phenomenon. However, the technique of Patent Document 2 needs to provide a part thicker than the other part of the can body and cannot be applied to a three-piece can.

したがって本発明の目的は、２ピース缶、３ピース缶のいずれにも適用可能であって、高いパネリング強度と軸座屈強度を兼ね備えた缶体を提供することにある。 Accordingly, an object of the present invention is to provide a can body that can be applied to both a two-piece can and a three-piece can and has both high paneling strength and axial buckling strength.

上記課題を解決するための本発明の要旨は以下のとおりである。
［1］円筒状の缶胴の１箇所以上に、缶胴全周に沿って突設された環状リブを有し、該環状リブは、１つの缶胴の一部を成形することにより形成されたものであり、かつ、缶胴の一部を缶胴軸線方向で折り重ねた構造を有し、缶胴面からの環状リブの突出長さが１ｍｍ以上であることを特徴とする缶体。
［2］上記［1］の缶体において、缶胴面からの環状リブの突出長さが５ｍｍ以下であることを特徴とする缶体。
［3］上記［1］または［2］の缶体において、缶胴平行部において環状リブで区画された部分の缶胴軸線方向での長さが４５ｍｍ以下であることを特徴とする缶体。 The gist of the present invention for solving the above problems is as follows.
[1] At least one cylindrical can body has an annular rib protruding along the entire circumference of the can body, and the annular rib is formed by molding a part of one can body. A can body characterized by having a structure in which a part of the can body is folded in the can body axis direction, and the protruding length of the annular rib from the can body surface is 1 mm or more.
[2] The can body according to [1], wherein the protruding length of the annular rib from the can body surface is 5 mm or less.
[3] A can body according to the above [1] or [2], wherein the length in the can body axis direction of a portion defined by the annular rib in the parallel portion of the can body is 45 mm or less.

本発明の缶体は、缶胴全周に沿って突設された環状リブが缶胴のパネリング強度を高めるとともに、この環状リブを構成する缶胴部分は缶胴軸線方向で折り重ねられ、閉じた構造となっているため、この部分から缶胴軸線方向での荷重に対して座屈することがない。このため高いパネリング強度と軸座屈強度を兼ね備えた缶体とすることができる。また、本発明の缶体は、環状リブを除く缶胴本体は通常の円筒缶胴と同様に平滑であるため、印刷や図柄を歪めることがないという利点もある。 In the can body of the present invention, an annular rib protruding along the entire circumference of the can body increases the paneling strength of the can body, and the can body portion constituting the annular rib is folded in the direction of the can body axis and closed. Therefore, it does not buckle against the load in the can axis direction from this portion. For this reason, it can be set as the can which has high paneling strength and axial buckling strength. Further, the can body of the present invention has an advantage that the can body main body excluding the annular rib is smooth like a normal cylindrical can body, so that printing and designs are not distorted.

本発明を３ピース缶に適用した場合の一実施形態を示す正面図The front view which shows one Embodiment at the time of applying this invention to a 3 piece can 図１の実施形態における環状リブが形成された缶胴部位の縦断面図The longitudinal cross-sectional view of the can body part in which the annular rib in the embodiment of FIG. 1 was formed 本発明の他の実施形態における環状リブが形成された缶胴部位の縦断面図The longitudinal cross-sectional view of the can body part in which the annular rib in other embodiment of this invention was formed 本発明の缶体の形態例（缶体の正面図）を示す説明図Explanatory drawing which shows the example (front view of a can) of the can of this invention 本発明の缶体が有する環状リブの成形方法の一例を示すものであって、成形工程を順に示す説明図Explanatory drawing which shows an example of the shaping | molding method of the annular rib which the can of this invention has, and shows a formation process in order 図５（Ａ），（Ｂ）の各成形工程での成形部の拡大縦断面図Enlarged longitudinal sectional view of the molding part in each molding step of FIGS. 5 (A) and 5 (B) ビード構造を備えた溶接缶の正面図Front view of welded can with bead structure

金属缶に必要な強度には、主として以下に挙げるような２つの種類がある。まず、缶内圧が負圧になる缶詰の場合に、缶胴が外圧によって凹まされる、いわゆるパネリング座屈に対抗するための缶強度がある。本発明ではこれをパネリング強度と呼ぶ。また、缶蓋を巻締固着する際に缶胴に上方（缶胴軸線方向）から外力が加えられることで、缶胴が軸線方向に押し潰されて座屈することに対抗する缶強度がある。本発明ではこれを軸座屈強度と呼ぶ。
本発明では、金属缶のコスト低減のために金属素材の板厚を低減するゲージダウンについて、３ピース缶の場合に現在用いられている最低レベルである０．１５ｍｍ程度の板厚を０．１０ｍｍまでゲージダウンすることを目標とした。 There are mainly two types of strength required for metal cans as described below. First, in the case of canning in which the internal pressure of the can is negative, there is a can strength to counter so-called paneling buckling in which the can body is recessed by external pressure. In the present invention, this is called paneling strength. Further, when the can lid is tightly fastened, an external force is applied to the can body from above (in the direction of the can body axis), so that the can body can withstand the buckling of the can body by being crushed in the axial direction. In the present invention, this is called axial buckling strength.
In the present invention, for gauge down to reduce the thickness of the metal material to reduce the cost of the metal can, the plate thickness of about 0.15 mm, which is the lowest level currently used in the case of a three-piece can, is 0.10 mm. The goal was to go down to gauge.

本発明を創案するに当たり、板厚０．１０ｍｍ、ＪＩＳ−Ｇ３３０３における調質度ＤＲ−８の原板を用いた錫めっき鋼板を用い、以下に示すような実験を行った。
まず、従来広く用いられているビード加工により缶体強度を向上させる技術の検証を行うため、ビード構造を備えた溶接缶を試作し、缶強度を測定した。ビードを備えた缶体の外観を図７（正面図）に示す。
試作した缶体は、缶胴内径ｄを５２．３８ｍｍ、巻締め部間の長さｅを８０ｍｍとし、内容量１４０ｇとなる缶に相当するものとした。また、ビードは、深さｆを０．６ｍｍ、ピッチｇを４ｍｍとし、缶胴の両端に缶蓋を巻き締めた状態の缶高さの６５％の範囲に成形した。比較のために、缶胴にビード加工の無い缶体も試作した。 In creating the present invention, the following experiment was performed using a tin-plated steel plate using a plate having a thickness of 0.10 mm and a tempering degree DR-8 in JIS-G3303.
First, in order to verify the technology for improving the strength of the can body by bead processing, which has been widely used in the past, a welded can having a bead structure was prototyped and the can strength was measured. FIG. 7 (front view) shows the appearance of a can body provided with a bead.
The prototype can body had a can body inner diameter d of 52.38 mm, a length e between the tightening portions of 80 mm, and corresponds to a can having an internal capacity of 140 g. The bead was formed in a range of 65% of the height of the can with a depth f of 0.6 mm, a pitch g of 4 mm, and a can lid wrapped around both ends of the can body. For comparison, a can body without a bead processing on the can body was also prototyped.

パネリング強度の測定は、以下のように行った。供試缶体は、試作した缶胴に内容物を充填せず、その両端に大気圧の下で蓋を巻締めで固着したものを用いた。供試缶体を空気圧で内部を加圧でき且つ内部の圧力を検出する圧力検出器を備えた容器の中に置き、容器を密閉した後、加圧を開始するとともに、容器内部の圧力の時間変化を測定し、加圧により缶体が座屈する際に生じる加圧容器内の急激な圧力変化（低下）が検出された後に加圧を停止した。この際、加圧の速度は１５．７ｋＰａ／ｓとした。パネリング強度は、前記の急激な圧力変化の直前の圧力とした。 The paneling strength was measured as follows. As the test can body, a prototype can body was not filled with contents, and lids were fixed to each end of the can body by tightening under atmospheric pressure. The test can body can be pressurized with air pressure and placed in a container equipped with a pressure detector that detects the internal pressure. After sealing the container, pressurization is started and the pressure inside the container is measured. The change was measured, and the pressurization was stopped after a sudden pressure change (decrease) in the pressurized container that occurred when the can was buckled by pressurization was detected. At this time, the pressurization speed was 15.7 kPa / s. The paneling strength was the pressure immediately before the sudden pressure change.

また、軸座屈強度の測定は、以下のように行った。供試缶体はパネリング強度の測定と同様のものを用いた。それぞれ水平な一対の加圧板を備え、それらが接近するように鉛直方向に移動することで物体を加圧することができ、且つ加圧に要する荷重を測定する荷重検出器を備えた圧縮試験機を用い、供試缶体を缶体軸線方向が鉛直になるように加圧板の間に置き、加圧を開始するとともに荷重の時間変化を測定し、加圧により缶体が座屈する際に生じる荷重変化点（荷重−時間線図の勾配の変化点）が検出された後に加圧を停止した。この際、加圧の速度は２０ｍｍ/ｍｉｎとした。軸座屈強度は、前記の荷重変化点の荷重とした。 Moreover, the axial buckling strength was measured as follows. The test can body was the same as the paneling strength measurement. A compression tester equipped with a pair of horizontal pressure plates, which can pressurize an object by moving in the vertical direction so that they approach each other, and has a load detector that measures the load required for pressurization. Use the test can body between the pressure plates so that the axial direction of the can body is vertical, start pressurization and measure the time change of the load, and the load change that occurs when the can body buckles due to pressurization The pressurization was stopped after a point (change point of gradient of load-time diagram) was detected. At this time, the pressurization speed was 20 mm / min. The shaft buckling strength was the load at the load change point.

パネリング強度、軸座屈強度の測定結果を表１に示す。ここで、それぞれの強度の合格基準は以下の値を採用した。パネリング強度は、缶に内容物を充填した後に行われる加熱殺菌処理であるレトルト処理時に缶に作用する圧力の代表的な値として、１４７ｋＰａを合格基準とした。また、軸座屈強度は、缶胴に対して蓋を取り付ける巻締め時に缶に作用する軸方向荷重の代表的な値として、１．４７ｋＮを合格基準とした。なお、これらの合格基準の値は缶の径、高さなどのサイズに関係なく設定される値である。これは、レトルト処理や巻締めが缶のサイズに拘わりなくほぼ一定の条件で行われていることによる。表１によれば、加工無しの缶体は、パネリング強度は合格基準を下回っているが、軸座屈強度は合格基準以上である。一方、ビード加工することにより、パネリング強度は向上して合格基準以上となる。しかし、軸座屈強度は低下して、合格基準を下回る値となる。このように、ビード加工はパネリング強度の向上には効果的であるが、一方で軸座屈強度を著しく低下させる。 Table 1 shows the paneling strength and axial buckling strength measurement results. Here, the following values were adopted as acceptance criteria for each strength. The paneling strength was 147 kPa as an acceptable standard as a representative value of the pressure acting on the can during the retort process, which is a heat sterilization process performed after filling the can with the contents. The axial buckling strength was 1.47 kN as an acceptable standard as a representative value of the axial load acting on the can when the lid is attached to the can body. In addition, these acceptance standard values are values set regardless of the size such as the diameter and height of the can. This is because retort processing and winding are performed under almost constant conditions regardless of the size of the can. According to Table 1, the paneling strength of the unprocessed can body is below the acceptance standard, but the axial buckling strength is above the acceptance standard. On the other hand, the beading improves the paneling strength and exceeds the acceptance standard. However, the axial buckling strength decreases and becomes a value below the acceptance standard. Thus, bead processing is effective in improving the paneling strength, but on the other hand, the shaft buckling strength is significantly reduced.

そこで、本発明者らは、パネリング強度と軸座屈強度を兼ね備えた缶体の構造について検討を行った。ビードは缶胴の剛性を高めるために効果的であるが、一方で軸座屈に関しては、ビード部分が変形の起点となって座屈が生じる。これに対して、缶胴の１箇所以上に、缶胴の一部を缶胴軸線方向で折り重ねた構造を有する環状リブを設けた構造とすることにより、上記ビードと同様の高いパネリング強度が得られる一方で、高い軸座屈強度を維持できることが判った。 Therefore, the present inventors examined the structure of a can body having both paneling strength and axial buckling strength. The bead is effective for increasing the rigidity of the can body, but with respect to the axial buckling, the bead portion is the starting point of deformation and buckling occurs. On the other hand, by having a structure in which an annular rib having a structure in which a part of the can body is folded in the can body axial direction is provided at one or more places on the can body, the same high paneling strength as the bead is provided. On the other hand, it was found that high axial buckling strength can be maintained.

図１および図２は本発明を３ピース缶に適用した場合の一実施形態を示すもので、図１は正面図、図２は環状リブが形成された缶胴部位の縦断面図である。図において、１は円筒状の缶胴、３ａ，３ｂは缶胴両端に接合される缶蓋の巻き締め部である。
この実施形態の缶体（金属缶）は、缶胴１の軸線方向（缶胴長手方向）のほぼ中央部に、缶胴内面の全周に沿って突設された環状リブ２を有している。この環状リブ２は、缶胴１の一部をその軸線方向で折り重ねた構造を有する。すなわち、この環状リブ２は、缶胴１の一部分を全周で缶胴内側に凸状に成形・突出させるとともに、この突出部分を、その上下の板部どうしが接するように扁平状に成形した（押し潰した）ものである。 1 and 2 show an embodiment in which the present invention is applied to a three-piece can. FIG. 1 is a front view, and FIG. 2 is a longitudinal sectional view of a can body portion where an annular rib is formed. In the figure, reference numeral 1 denotes a cylindrical can body, and 3a and 3b denote can lid tightening portions joined to both ends of the can body.
The can body (metal can) of this embodiment has an annular rib 2 protruding along the entire circumference of the inner surface of the can body at a substantially central portion in the axial direction (can body longitudinal direction) of the can body 1. Yes. The annular rib 2 has a structure in which a part of the can body 1 is folded in the axial direction. That is, the annular rib 2 is formed so that a part of the can body 1 protrudes and protrudes inside the can body on the entire circumference, and the protruding portion is formed in a flat shape so that the upper and lower plate portions are in contact with each other. (Crushed).

本実施形態の環状リブ２は、缶胴部分を２重に折り重ねた構造であるが、より多重に折り重ねた構造としてもよい。
図３は、本発明の他の実施形態を示すものであり、環状リブが形成された缶胴部位の縦断面図である。この実施形態の環状リブ２は、缶胴部分を４重に折り重ねた構造を有する。すなわち、この環状リブ２は、缶胴軸線方向で隣接した２箇所において、缶胴の一部分を全周で缶胴内側に凸状に成形・突出させるとともに、この２つの突出部分を、各々の上下の板部どうしが接し、且つ２つの突出部分どうしも接するように扁平状に成形した（押し潰した）ものである。
このように缶胴部分を多重に折り重ねた構造の環状リブ２は、特にパネリング強度の向上に有効である。 Although the annular rib 2 of the present embodiment has a structure in which the can body portion is folded twice, a structure in which the can body portion is folded more than once may be used.
FIG. 3 shows another embodiment of the present invention, and is a longitudinal cross-sectional view of a can body portion where an annular rib is formed. The annular rib 2 of this embodiment has a structure in which the can body portion is folded four times. That is, the annular rib 2 is formed so that a part of the can body is formed and protruded in a convex shape on the inside of the can body at two locations adjacent to each other in the axial direction of the can body. Are formed into flat shapes (crushed) so that the plate portions are in contact with each other and the two protruding portions are also in contact with each other.
Thus, the annular rib 2 having a structure in which the can body portion is folded in multiple is particularly effective in improving the paneling strength.

図７に代表的な構造を示したビードは、平滑な缶胴面に対して凹凸状に成形され、ビード構造自体が缶胴面の一部を構成している。このビードは、本発明の缶体が有する環状リブ２と同様に缶胴の剛性を高め、これによってパネリング強度の向上に寄与するが、その凹部・凸部が缶胴内側・外側に開いた構造であるため、缶胴軸線方向での荷重に対して容易に座屈してしまう。これに対して、本発明の缶体が有する環状リブ２は、ビードと同じく缶胴１の一部を変形させたものであり、缶胴１のパネリング強度を高めるが、それを構成する缶胴部分は缶胴軸線方向で折り重ねられ、閉じた構造となっており、環状リブ２は実質的に缶胴面を構成していない。このため缶胴１は、缶胴体軸線方向での荷重に対して環状リブ２の部位から座屈することがない。以上の点から、本発明の缶体は高いパネリング強度と軸座屈強度を兼ね備えたものとなる。また、本発明の缶体は、環状リブを除く缶胴本体は通常の円筒缶胴と同様に平滑であるため、印刷や図柄を歪めることがないという利点もある。 The bead whose typical structure is shown in FIG. 7 is formed in a concavo-convex shape with respect to a smooth can body surface, and the bead structure itself constitutes a part of the can body surface. This bead increases the rigidity of the can body in the same manner as the annular rib 2 of the can body of the present invention, thereby contributing to the improvement of the paneling strength. Therefore, it will buckle easily with respect to the load in the can barrel axis direction. On the other hand, the annular rib 2 included in the can body of the present invention is obtained by deforming a part of the can body 1 like the bead and increases the paneling strength of the can body 1. The portion is folded in the can barrel axis direction and has a closed structure, and the annular rib 2 does not substantially constitute the can barrel surface. For this reason, the can body 1 does not buckle from the site | part of the annular rib 2 with respect to the load in a can body axis direction. From the above points, the can body of the present invention has both high paneling strength and axial buckling strength. Further, the can body of the present invention has an advantage that the can body main body excluding the annular rib is smooth like a normal cylindrical can body, so that printing and designs are not distorted.

本発明の缶体の缶強度（パネリング強度、軸座屈強度）を先に述べたと同様の方法で測定した。その測定結果を表１に併せて示す。ここで、供試缶体は、板厚０．１ｍｍ、ＪＩＳ−Ｇ３３０３における調質度ＤＲ−８の原板を用いた錫めっき鋼板を製缶した溶接缶であり、缶胴内径を５２．３８ｍｍ、巻締め部間の長さを８０ｍｍとし、内容量１４０ｇとなる缶に相当するものとした。環状リブ２は、缶胴軸線方向の中央部位置に、缶内側に向けて突出するように成形し、缶胴面からの突出長さを１．５ｍｍとした。表１に示されるように、本発明の缶体のパネリング強度は、加工無しの缶体に較べて大きく向上し、合格基準に達しおり、また、軸座屈強度は加工無しの缶体よりも若干低いものの、これも合格基準に達している。 The can strength (paneling strength, axial buckling strength) of the can body of the present invention was measured by the same method as described above. The measurement results are also shown in Table 1. Here, the test can body is a welded can made of a tin-plated steel plate using an original plate having a thickness of 0.1 mm and a tempering degree of DR-8 in JIS-G3303, and the inner diameter of the can body is 52.38 mm. The length between the winding parts was 80 mm, and it corresponded to a can having an internal capacity of 140 g. The annular rib 2 was formed so as to protrude toward the inner side of the can at the center position in the can axis direction, and the protruding length from the can body surface was 1.5 mm. As shown in Table 1, the paneling strength of the can body of the present invention is greatly improved as compared with the can body without processing, and has reached the acceptance criteria, and the axial buckling strength is higher than that of the can body without processing. Although it is a little low, it has also passed the acceptance criteria.

本発明の缶体では、環状リブ２を缶胴軸線方向の２箇所に設けることができる。この環状リブ２の本数は、必要とされる強度や後述する部分ｐの長さＬなどに応じて適宜選択すればよい。
また、上述した実施形態では、環状リブ２は缶胴内面側に突出するように形成してあるが、反対に、缶胴外面側に突出するように形成してもよい。この場合には、缶胴１の一部分を全周で缶胴外側に凸状に成形・突出させるとともに、この突出部分を、その上下の板部どうしが接するように扁平状に成形する（押し潰す）ことで、缶胴１の一部をその軸線方向で折り重ねた構造の環状リブ２を形成する。また、缶胴軸線方向の複数箇所に環状リブ２を設けるとともに、一部の環状リブ２を缶胴内面側に、他の環状リブ２を缶胴外面側にそれぞれ突出するように形成してもよい。環状リブ２を缶胴内面側・外面側のいずれに突出させるかは、缶体の意匠性などを考慮して適宜決めればよい。 In the can body of the present invention, the annular ribs 2 can be provided at two locations in the can barrel axis direction. The number of the annular ribs 2 may be appropriately selected according to the required strength, the length L of the portion p described later, and the like.
In the above-described embodiment, the annular rib 2 is formed so as to protrude toward the inner surface of the can body, but on the contrary, it may be formed so as to protrude toward the outer surface of the can body. In this case, a part of the can body 1 is formed and projected in a convex shape on the outer periphery of the can body, and the projecting portion is formed into a flat shape so that the upper and lower plate portions are in contact with each other (crushing). Thus, the annular rib 2 having a structure in which a part of the can body 1 is folded in the axial direction is formed. Further, the annular ribs 2 may be provided at a plurality of locations in the can barrel axis direction, and a part of the annular ribs 2 may be protruded toward the inner surface of the can barrel and the other annular ribs 2 may be protruded toward the outer surface of the can barrel. Good. Whether the annular rib 2 protrudes on the inner surface side or the outer surface side of the can body may be determined as appropriate in consideration of the design of the can body.

本発明の缶体では環状リブ２の缶胴面からの突出長さａ（缶胴径方向での突出高さ）は１ｍｍ以上とする。この突出長さａが１ｍｍ未満では、パネリング強度の向上効果が小さい。これは、このような突出長さａが小さい環状リブ２では、リブ自体の強度が低いため、缶胴１の剛性を十分に高めることができないためであると考えられる。
一方、突出長さａ大きすぎるとパネリング強度の向上効果が小さくなる。これは、突出長さａが大きくなると、環状リブ２の構造が缶胴周方向で不均一になりやすくなることが原因であると考えられる。このため突出長さａは５ｍｍ以下であることが好ましい。
本発明の缶体において、環状リブ２は、缶胴１の周方向で均一な突出長で形成されることが望ましい。 In the can body of the present invention, the protruding length a of the annular rib 2 from the can body surface (the protruding height in the can body radial direction) is 1 mm or more. When the protruding length a is less than 1 mm, the effect of improving the paneling strength is small. This is considered to be because the annular rib 2 having such a small protruding length a cannot sufficiently increase the rigidity of the can body 1 because the strength of the rib itself is low.
On the other hand, if the protrusion length a is too large, the effect of improving the paneling strength is reduced. This is considered to be caused by the fact that the structure of the annular rib 2 tends to be non-uniform in the circumferential direction of the can body when the protruding length a is increased. For this reason, it is preferable that the protrusion length a is 5 mm or less.
In the can body of the present invention, the annular rib 2 is preferably formed with a uniform protruding length in the circumferential direction of the can body 1.

また、缶胴平行部において環状リブ２で区画された部分ｐ（缶胴部分）の缶胴軸線方向での長さＬが４５ｍｍ以下であることが好ましい。図４（イ）〜（ハ）は、本発明の缶体の形態例（缶体の正面図）を示すものである。缶胴平行部とは、径が一定の缶胴部分を指し、図４（イ）、図４（ハ）のように缶胴全体の径が一定である場合には、缶胴全体＝缶胴平行部である。一方、図４（ロ）のように缶胴両端に縮径したネック部１００を有する場合には、このネック部１００を除いた部分が缶胴平行部である。 Moreover, it is preferable that the length L in the can body axis direction of the part p (can body part) divided by the annular rib 2 in the can body parallel part is 45 mm or less. 4A to 4C show an example of the can body according to the present invention (a front view of the can body). The can body parallel part means a can body portion having a constant diameter. When the diameter of the entire can body is constant as shown in FIGS. 4 (a) and 4 (c), the entire can body = can body It is a parallel part. On the other hand, when the neck portion 100 having a reduced diameter is provided at both ends of the can body as shown in FIG. 4B, the portion excluding the neck portion 100 is a can body parallel portion.

図４（イ）〜（ハ）に、缶胴平行部において環状リブ２で区画された部分ｐの缶胴軸線方向での長さＬを示す。図４（イ）のように缶胴全体＝缶胴平行部で且つ環状リブ２が１本である場合には、部分ｐの長さＬは、環状リブ２の中央部から巻き締め部３ａ，３ｂの各端面までの長さである。図４（ロ）のように缶胴両端にネック部１００を有する場合には、部分ｐの長さＬは、環状リブ２の中央部から各ネック部１００の基端部までの長さである。また、図４（ハ）のように環状リブ２が２本以上ある場合には、隣接する２本の環状リブ２の中央部間の長さも、部分ｐの長さＬとなる。 4A to 4C show the length L of the portion p defined by the annular rib 2 in the can barrel parallel portion in the can barrel axis direction. When the entire can body = can body parallel portion and one annular rib 2 as shown in FIG. 4 (a), the length L of the portion p is set from the central portion of the annular rib 2 to the tightening portions 3a, It is the length to each end surface of 3b. When the neck portion 100 is provided at both ends of the can body as shown in FIG. 4B, the length L of the portion p is the length from the center portion of the annular rib 2 to the base end portion of each neck portion 100. . When there are two or more annular ribs 2 as shown in FIG. 4C, the length between the central portions of the two adjacent annular ribs 2 is also the length L of the portion p.

本発明の缶体は、環状リブ２で区画される２つ以上の部分ｐを有することになるが、環状リブ２を設ける缶胴軸線方向での位置や、環状リブ２の本数は任意であるので、部分ｐの缶胴軸線方向での長さＬも基本的に任意である。一方、本発明者らによる検討の結果、環状リブ２を設けることによる缶体のパネリング強度の向上効果は、部分ｐの缶胴軸線方向での長さＬによって異なり、長さＬが４５ｍｍを超えるような部分ｐが存在すると、缶体のパネリング強度の向上効果が低下することが判った。ここで、長さＬが４５ｍｍを超える部分ｐが存在する場合としては、複数ある部分ｐのうちの一部の部分ｐ（例えば、２つある部分ｐのうち１つの部分ｐ）の長さＬが４５ｍｍを超える場合と、複数ある部分ｐの全部の長さＬが４５ｍｍを超える場合がある。 The can body of the present invention has two or more portions p defined by the annular rib 2, but the position of the annular rib 2 in the can barrel axis direction and the number of the annular ribs 2 are arbitrary. Therefore, the length L of the portion p in the can barrel axis direction is basically arbitrary. On the other hand, as a result of the study by the present inventors, the effect of improving the paneling strength of the can body by providing the annular rib 2 differs depending on the length L of the portion p in the can barrel axis direction, and the length L exceeds 45 mm. It was found that when such a portion p was present, the effect of improving the paneling strength of the can was reduced. Here, as a case where there is a portion p having a length L exceeding 45 mm, the length L of a portion p of the plurality of portions p (for example, one portion p of the two portions p). May exceed 45 mm, and the total length L of the plurality of portions p may exceed 45 mm.

長さＬが４５ｍｍを超える部分ｐが存在すると、パネリング強度の向上効果が低下するのは、各々の部分ｐは補強構造のない平坦な領域であるためパネリング強度が弱く、その長さＬがある程度大きくなると、単位面積あたり作用する外圧が同じでも外圧によって作用する力が増大するためである。
このことからして、パネリング強度の面では部分ｐの長さＬは短いほど有利である。しかし、部分ｐの長さを短くするには、缶胴１の長さを短くするか、環状リブ２の本数を増やす必要があるが、前者は必要な内容量を確保できなくなるという点で現実的ではなく、また、後者はコストの上昇を招く問題がある。したがって、これらの観点から、部分ｐの長さＬは１０ｍｍ以上とすることが望ましい。 If there is a portion p having a length L exceeding 45 mm, the effect of improving the paneling strength is lowered because each portion p is a flat region without a reinforcing structure, and the paneling strength is weak, and the length L is somewhat This is because the force applied by the external pressure increases even when the external pressure applied per unit area is the same as the value increases.
Therefore, the shorter the length L of the portion p, the more advantageous in terms of paneling strength. However, in order to shorten the length of the portion p, it is necessary to shorten the length of the can body 1 or increase the number of the annular ribs 2, but the former is a reality in that a necessary internal capacity cannot be secured. In addition, the latter has a problem of increasing costs. Therefore, from these viewpoints, the length L of the portion p is desirably 10 mm or more.

また、缶胴１の縦断面において、環状リブ２は缶胴本体に対して直角であることが好ましい。また、環状リブ２の基端部２０、すなわち環状リブ２が缶胴本体から立ち上がるコーナー部の曲率は、軸座屈強度の面では小さい方が望ましいが、缶胴の表面被覆を損傷させないようにするという観点からは、缶胴１の素材板厚ｔの０．５倍以上とすることが望ましい。また、同様な理由から、環状リブ２の先端部２１は、缶胴１の素材板厚ｔの１倍以上の曲率とすることが望ましい。 Further, in the longitudinal section of the can body 1, the annular rib 2 is preferably perpendicular to the can body main body. Further, the curvature of the base end portion 20 of the annular rib 2, that is, the corner portion where the annular rib 2 rises from the can body main body is preferably small in terms of the axial buckling strength, but the surface covering of the can body is not damaged. From the viewpoint of doing, it is desirable that the thickness of the material thickness t of the can body 1 is 0.5 times or more. For the same reason, it is desirable that the tip 21 of the annular rib 2 has a curvature that is at least one times the material thickness t of the can body 1.

環状リブ２を缶胴１に成形する方法は任意であるが、例えば、図５および図６に示すような方法で成形することができる。図５（Ａ），（Ｂ）は成形工程を順に示す説明図、図６（Ａ），（Ｂ）は図５（Ａ），（Ｂ）の各成形工程での成形部の拡大縦断面図である。
まず、図５（Ａ）、図６（Ａ）に示すように、外周に断面山形状の環状凸条４０（雄型）を備えた円筒状の外型４を缶胴１の外側に、外周に断面谷形状の環状溝５０（雌型）を備えた円筒状の内型５を缶胴１の内側に、それぞれ配置し、これら外型４と内型５で缶胴１を挟圧し、環状凸条４０と環状溝５０で缶胴部分を缶胴内側に断面山形状に突出させる予備成形加工を施す（この予備成形加工部２xを図５（Ｂ）、図６（Ｂ）に示す）。そして、このように缶胴１を挟圧した状態で外型４と内型５を回転させることで、缶胴１の全周にわたり環状凸条４０と環状溝５０による上述したような予備成形加工がなされる。 Although the method of shaping | molding the annular rib 2 to the can body 1 is arbitrary, it can shape | mold by the method as shown in FIG. 5 and FIG. 6, for example. FIGS. 5A and 5B are explanatory views showing the molding process in order, and FIGS. 6A and 6B are enlarged longitudinal sectional views of the molding part in each molding process of FIGS. 5A and 5B. It is.
First, as shown in FIGS. 5 (A) and 6 (A), a cylindrical outer mold 4 having an annular ridge 40 (male mold) having a cross-sectional mountain shape on the outer periphery is disposed outside the can body 1. A cylindrical inner mold 5 provided with an annular groove 50 (female mold) having a valley cross section is disposed inside the can body 1, and the can body 1 is sandwiched between the outer mold 4 and the inner mold 5 to form an annular shape. The preform 40 and the annular groove 50 are subjected to a preforming process in which the can body portion protrudes in a cross-sectional shape inside the can body (this preforming portion 2x is shown in FIGS. 5B and 6B). Then, by rotating the outer mold 4 and the inner mold 5 with the can body 1 sandwiched in this manner, the preforming process as described above is performed by the annular ridges 40 and the annular grooves 50 over the entire circumference of the can body 1. Is made.

次いで、図５（Ｂ）、図６（Ｂ）に示すように、円筒状の挟圧型６を缶胴１の内側に配置し、この挟圧型６で上記予備成形加工部２xを上下方向で挟圧し、扁平状に成形する（押し潰す）。挟圧型６は、軸線方向で接離可能な上型６０と下型６１を有し、これら上型６０と下型６１で上記予備成形加工部２ｘを上下方向で挟圧しつつ、挟圧型６を回転させることにより、缶胴１の全周にわたり予備成形加工部２xが扁平状に成形され（押し潰され）、環状リブ２が形成される。
なお、缶外面側に環状リブ２を形成する場合には、図５および図６とは逆に、内型５の外周に断面山形状の環状凸条を設け、外型４の外周に断面谷形状の環状溝を設け、これらにより缶胴部分の予備成形加工を行い、しかる後、缶胴外側に配置した挟圧型６で予備成形加工部を上下に挟圧し、これを扁平状に成形すればよい。 Next, as shown in FIGS. 5B and 6B, a cylindrical clamping die 6 is arranged inside the can body 1, and the preforming portion 2x is sandwiched between the clamping die 6 in the vertical direction. Press and shape into a flat shape (crush). The clamping die 6 has an upper die 60 and a lower die 61 that can be contacted / separated in the axial direction. The clamping die 6 is sandwiched between the upper die 60 and the lower die 61 while clamping the preforming portion 2x in the vertical direction. By rotating, the preforming portion 2x is formed flat (crushed) over the entire circumference of the can body 1, and the annular rib 2 is formed.
When the annular rib 2 is formed on the outer surface of the can, contrary to FIGS. 5 and 6, an annular protrusion having a cross-sectional mountain shape is provided on the outer periphery of the inner mold 5, and a sectional valley is formed on the outer periphery of the outer mold 4. An annular groove having a shape is provided, and a preforming process of the can body portion is performed by these, and then the preforming processing portion is vertically pressed by a sandwiching die 6 disposed outside the can body, and this is formed into a flat shape. Good.

本発明の缶体に用いる金属素材に特別な制限はないが、耐食性確保の観点からは、金属素材として表面処理鋼板を用いるのが望ましい。表面処理としては、例えば、錫、亜鉛、ニッケル、クロム、或いはそれらの合金の１種または２種以上によるめっき処理が好ましく、さらに、その上層にクロメート処理やリン酸塩処理のような化成処理を施したものも好適である。表面処理鋼板としては、特に、従来から飲料容器に用いられている錫めっき鋼板（ぶりき）、電解クロメート処理鋼板（ティンフリー・スチール）が好適である。また、各種表面処理鋼板に、樹脂フィルムを被覆したラミネート鋼板が、耐食性や環境適合性など面から特に好適である。 Although there is no special restriction | limiting in the metal raw material used for the can of this invention, It is desirable to use a surface treatment steel plate as a metal raw material from a viewpoint of ensuring corrosion resistance. As the surface treatment, for example, plating treatment with one or more of tin, zinc, nickel, chromium, or an alloy thereof is preferable, and further, chemical conversion treatment such as chromate treatment or phosphate treatment is performed on the upper layer. Those applied are also suitable. As the surface-treated steel sheet, tin-plated steel sheets (tinplate) and electrolytic chromate-treated steel sheets (tin-free steel) that are conventionally used in beverage containers are particularly suitable. In addition, laminated steel plates obtained by coating various surface-treated steel plates with resin films are particularly suitable from the viewpoint of corrosion resistance and environmental compatibility.

本発明を３ピース缶に適用する場合、素材鋼板の板厚は、容器の軽量化の観点から０．０８５〜０．１５５ｍｍが好適である。
長方形の鋼板を素材とし、その対向する端部を接合して円筒とする方法は、十分な接合強度を備えた方法であれば特に規定しないが、溶接法、接着法、半田法などを用いことができる。これらのうち、特に接合強度の高い溶接法が好適である。溶接法としては、シーム溶接などの通電溶接や、レーザー溶接を適用することができる。 When the present invention is applied to a three-piece can, the thickness of the material steel plate is preferably 0.085 to 0.155 mm from the viewpoint of reducing the weight of the container.
The method of using a rectangular steel plate as a raw material and joining its opposite ends into a cylinder is not particularly limited as long as it has sufficient joint strength, but welding, bonding, soldering, etc. should be used. Can do. Among these, a welding method with particularly high joint strength is suitable. As the welding method, current welding such as seam welding or laser welding can be applied.

また、本発明を２ピース缶に適用する場合、缶胴部は絞り加工などで成形されることになる。その際、缶胴部と元の鋼板の板厚は異なる。本発明の目的は缶体の軽量化にあるため、缶胴部を元の板厚よりも薄くすることが望ましい。その際の缶胴部の板厚は０．０８５〜０．１５５ｍｍが好適である。この缶胴部の板厚を得るためには、元の鋼板板厚は０．１８〜０．２４ｍｍ程度であることが望ましい。２ピース缶を得るための絞り加工の方法には、ＤＲＤ（Draw and Redraw）加工法、ＤＴＲ(Draw and Thin Redraw)加工法、ＤＩ（Draw and Ironing）加工法、ストレッチドロー加工法、薄肉化深絞りしごき加工法などを適用することができる。缶胴を元の板厚よりも薄くするため、絞り加工後にしごき加工を行うＤＩ加工或いは薄肉化深絞りしごき加工法などが望ましい。 When the present invention is applied to a two-piece can, the can body is formed by drawing or the like. In that case, the plate | board thickness of a can trunk | drum and an original steel plate differs. Since the object of the present invention is to reduce the weight of the can body, it is desirable to make the can body portion thinner than the original plate thickness. The plate thickness of the can body at that time is preferably 0.085 to 0.155 mm. In order to obtain the plate thickness of the can body, the original steel plate thickness is preferably about 0.18 to 0.24 mm. Drawing methods for obtaining two-piece cans include DRD (Draw and Redraw), DTR (Draw and Thin Redraw), DI (Draw and Ironing), stretch draw, thinning depth A drawing ironing method can be applied. In order to make the can body thinner than the original plate thickness, DI processing in which ironing is performed after drawing or a deep-thickening deep drawing ironing method is desirable.

［実施例１］
板厚０．１０ｍｍ、ＪＩＳ−Ｇ３３０３における調質度ＤＲ−８の鋼板に錫めっき付着量１．１ｇ／ｍ^２の錫めっきを施し、この錫めっき鋼板の両面に、後に溶接される部分を除いてＰＥＴフィルムを熱融着法でラミネートしたラミネート鋼板を素材とし、缶内径５２．３８ｍｍ、６６．２５ｍｍの溶接缶胴を製造した。この溶接缶胴に対して、溶接部の内面補修塗装およびその焼付けを行った後、図５および図６に示す方法で環状リブを成形加工した。溶接缶胴の両端に缶蓋を巻き締め、表１に関する試験と同じ方法でパネリング強度と軸座屈強度を測定した。その結果を、缶内径、環状リブの構成などとともに表２に示す。なお、表２において、環状リブの本数：０の実施例（Ｎｏ．７，Ｎｏ．９，Ｎｏ．１５）は、環状リブを設けなかった比較例の缶体である。パネリング強度の評価は、１４７ｋＰａ以上を“合格”（○）、１５７ｋＰａ以上を“特に優れる”（◎）とした。
表２によれば、溶接缶胴に環状リブを設けた本発明例の缶体は、軸座屈強度が低下することなく、パネリング強度が向上していることが判る。なかでも、環状リブの突出長さａが５ｍｍ以下で且つ部分ｐの長さＬが４５ｍｍ以下である本発明例の缶体は、特に優れた缶強度を有している。 [Example 1]
A steel plate having a thickness of 0.10 mm and a tempering degree of DR-8 according to JIS-G3303 was subjected to tin plating with a tin plating adhesion amount of 1.1 g / m ² , and the portions to be welded later on both surfaces of the tin plated steel plate were excluded. Using a laminated steel sheet obtained by laminating a PET film by a heat fusion method, a welded can body having a can inner diameter of 52.38 mm and a 66.25 mm was manufactured. After this inner surface repair coating of the welded portion and its baking were performed on the welded can body, an annular rib was formed by the method shown in FIGS. 5 and 6. Can lids were wrapped around both ends of the welded can body, and paneling strength and axial buckling strength were measured in the same manner as in the test related to Table 1. The results are shown in Table 2 together with the inner diameter of the can and the configuration of the annular rib. In Table 2, the examples (No. 7, No. 9, No. 15) of the number of annular ribs: 0 are cans of comparative examples in which no annular rib is provided. The paneling strength was evaluated as “pass” (◯) when 147 kPa or higher and “particularly excellent” (（) when 157 kPa or higher.
According to Table 2, it can be seen that the can body of the present invention example in which the annular rib is provided on the welded can body has improved paneling strength without lowering the axial buckling strength. Especially, the can body of the present invention example in which the protruding length a of the annular rib is 5 mm or less and the length L of the portion p is 45 mm or less has particularly excellent can strength.

［実施例２］
板厚０．２１ｍｍ、ＪＩＳ−Ｇ３３０３における調質度Ｔ−３ＣＡの鋼板にクロムめっきを施し、金属クロム付着量とクロム水酸化物付着量がそれぞれクロム換算で１２０ｍｇ／ｍ^２、１５ｍｇ／ｍ^２のティンフリースチールとした後、その両面にＰＥＴフィルムを熱融着法でラミネートしたラミネート鋼板を素材として用いた。このラミネート鋼板の表面に加工潤滑剤となるパラフィンワックスを塗布した後、薄肉化深絞りしごき加工により、缶内径５２．３８ｍｍ、６６．２５ｍｍの絞り缶胴を製造した。この絞り缶胴に対し、パラフィンワックスを除去するために２００℃で３分の熱処理を施した後、図５および図６に示す方法で環状リブを成形加工した。絞り缶胴の一端に缶蓋を巻き締め、表１に関する試験と同じ方法でパネリング強度と軸座屈強度を測定した。その結果を、缶内径、環状リブの構成などとともに表３に示す。なお、表３において、環状リブの本数：０の実施例（Ｎｏ．２３，Ｎｏ．２５，Ｎｏ．３１）は、環状リブを設けなかった比較例の缶体である。パネリング強度の評価は、実施例１と同様とした。
表３によれば、絞り缶胴に環状リブを設けた本発明例の缶体は、軸座屈強度が低下することなく、パネリング強度が向上していることが判る。なかでも、環状リブの突出長さａが５ｍｍ以下で且つ部分ｐの長さＬが４５ｍｍ以下である本発明例の缶体は、特に優れた缶強度を有している。 [Example 2]
Thickness 0.21mm, JIS-G3303 subjected to chrome plating steel sheet temper T-3CA in metal chromium coating weight and chromium hydroxide coating weight of each terms of chromium 120 mg ^/ m 2, of 15 mg / ^{m 2} After using tin-free steel, a laminated steel plate in which PET films were laminated on both sides by a heat-sealing method was used as a material. After applying paraffin wax as a processing lubricant to the surface of the laminated steel sheet, a drawn can body having a can inner diameter of 52.38 mm and 66.25 mm was manufactured by thinning and deep drawing ironing. The drawn can body was heat treated at 200 ° C. for 3 minutes to remove paraffin wax, and then the annular rib was formed by the method shown in FIGS. A can lid was wound around one end of the drawn can body, and the paneling strength and the axial buckling strength were measured by the same method as the test related to Table 1. The results are shown in Table 3 together with the inner diameter of the can and the configuration of the annular rib. In Table 3, Examples (No. 23, No. 25, No. 31) in which the number of annular ribs is 0 are cans of comparative examples in which no annular rib is provided. The paneling strength was evaluated in the same manner as in Example 1.
According to Table 3, it can be seen that the can body according to the present invention in which the annular can is provided with the annular rib has improved paneling strength without lowering the axial buckling strength. Especially, the can body of the present invention example in which the protruding length a of the annular rib is 5 mm or less and the length L of the portion p is 45 mm or less has particularly excellent can strength.

１缶胴
２環状リブ
２x 予備成形加工部
３ａ，３ｂ巻き締め部
４外型
５内型
６挟圧型
２０基端部
２１先端部
４０環状凸条
５０環状溝
６０上型
６１下型
１００ネック部
ｐ部分 DESCRIPTION OF SYMBOLS 1 Can body 2 Annular rib 2x Preliminary shaping | molding process part 3a, 3b Winding part 4 Outer type | mold 5 Inner type | mold 6 Clamping type | mold 20 Base end part 21 Tip part 40 Annular ridge 50 Annular groove 60 Upper mold | type 61 Lower mold | type 100 Neck part p portion

Claims

At least one cylindrical can body has an annular rib protruding along the entire circumference of the can body, and the annular rib is formed by molding a part of one can body. A can body having a structure in which a portion of the can body is folded in the direction of the can body axis , and the protruding length of the annular rib from the can body surface is 1 mm or more.

The can body according to claim 1, wherein the protruding length of the annular rib from the can body surface is 5 mm or less.

The can body according to claim 1 or 2, wherein a length in a can body axis direction of a portion partitioned by the annular rib in the can body parallel part is 45 mm or less.