JP4316904B2 - Rubber coated steel cord manufacturing apparatus, cord, rubber ribbon using the cord, and tire manufacturing method using the same - Google Patents

Description

ゴム侵入率とコード疲労性の試験方法は、下記の方法を採用した。
ゴム侵入率：表１の各比較例及び各実施例に定義の構造、素線径及び撚りピッチを持つ４種類のコードの各々を使用して後述するタイヤの生産方法により空気入りラジアルタイヤを生産した。この４種類のタイヤの各々からゴムが付着した状態でスチールコードを取り出した。このゴム付きスチールコードの表面からゴムを除去した後、１本、２本と素線を注意深く取り除き、約１０ｃｍ長さの上記サンプルを観察して、空隙にゴムが完全に充填されている長さを測定した。ゴムが充填されている部分のサンプル全長に対する比率を、ゴム侵入率とした。
【００４４】
コード疲労性：図６に示すコード疲労試験装置７０を用いる。パイロットバー７１上を水平移動するスライダ７２に３個のローラ７３を自由回転可能に支持し、加硫したゴム被覆スチールコードサンプルをこれら３個のローラ７３間に巻装すると共に、同サンプルの一端を固定し、他端を所定重量の錘７４で緊張する。スライダ７２を所定ストロークＬだけ左右に往復動させ、コード切断までの往復動回数を求めた。評価は、比較例１を１００とした場合における比較例２、実施例１及び２の相対評価を指数で示した。
【００４５】
これらの試験結果から、ゴム侵入率とコード疲労性とが関連し、ゴム侵入率が最も良い実施例１は、比較例１に対し耐久性が３割向上したことを確認した。また、実施例２は、撚り維持具なしで比較例２よりも１割程度の耐久性向上を達成することが確認された。これらの試験により、実施例１及び２は何れも比較例１及び２よりも耐久性において優れていることを確認した。
【００４６】
（第２の実施形態）
図７は、コード製造方法の第２の実施形態における要部拡大図を示す。回転バレル２４は１２個のボビンを内装し、その前端面に設けた小径ピッチ円上の等間隔の３個の送出穴及び大径ピッチ円上の９個の送出穴からはそれぞれ素線１２を回転軸線に収集させるように送出している。大径ピッチ円上の９個の送出穴の配置関係は、図８のような撚り構造を得るようにバレル２４の回転速度とドラム６１の巻き取り速度との関係において決定される。押出機５０の押出型ヘッド５１は、回転バレル２４の回転軸線上に撚り維持具５５を配置している。撚り維持具５５は、同心配置の内外２つの円筒５５１、５５２からなり、軸受部材５５４を介して外円筒５５２が回転自在に支持され、この外円筒５５２の内孔に軸受部材５５３を介して内円筒５５１が回転自在に支持されている。内円筒５５１には、図５に示したものと同様に、円周方向等間隔（１２０度）配置の３つの素線ガイド穴５５１ａが貫通して形成され、外円筒５５２には円周方向等間隔（４０度）配置の９つの素線ガイド穴５５２ａが貫通して形成されている。回転バレル２４の前端面の外周縁部から１２０度間隔の３つの送出穴から送り出される素線１２は、内円筒５５１の３つの素線ガイド穴５５１ａへ導入され、この内円筒５５１を貫通し、そこから撚り合わせダイス５６のコード送出穴５６ａに導入されている。回転バレル２４の前端面の外周円縁部にある残りの９つの送出穴から送り出される素線１２は、外円筒５５２の円周方向４０度間隔で形成されえた９つの素線ガイド穴５５２ａへ導入され、これらガイド穴５５２ａを貫通してからダイス５６のコード送出穴５６ａに導入されている。
【００４７】
未加硫ゴムが圧送充満された雰囲気の中に撚り維持具５５の内外円筒５５１、５５２の後端部を臨ませるように、ゴム供給部５７ａは撚り維持具５５の後端部を収容する円盤状の空間とされ、図略のスクリューポンプから未加硫ゴムが供給されるように形成されている。このゴム供給部５７ａは、回転バレル２４軸線周りでの素線１２の回転を許容するテーパ円筒空間として形成されたテーパ通路５７ｂを介して同じく円盤状の空間をなすゴム注入部５７ｃへ未加硫ゴムを圧送するように接続されている。ダイス５６のコード送出穴５６ａからは、張力付与装置６０の巻き取りロール６１により巻き取られるスチールコード１０が送出される。
【００４８】
すなわち、回転バレル２４が張力付与装置６０によるスチールコード１０の巻き取り速度に同期した所定の速度で回転されるとき、内円筒５５１及び外円筒５５２は素線１２の張力を受けて連れ周り回転される。この場合、これら円筒５５１及び５５２を通過した素線１2は、ダイス５６のコード送出穴５６ａに向けて送られながらこのコード送出穴５６ａを基点とし旋回するため、互いに撚り合わされる。内円筒５５１を通過した芯材となる３本の素線１２は、径方向の離散が小さいため、径方向の離散が大きな外円筒５５２を通過した９本の素線１２よりも、早く撚り合わされる。つまり、内円筒５５１と外円筒５５２の径差、より正確には、素線ガイド穴５５１ａを配置する円と素線ガイド穴５５２ａを配置する円との径の差によって、内側３本の素線１２の撚り合わせ動作と外側９本の素線１２撚り合わせ動作が僅かな時間差をもって異なるタイミングで行われる。この撚り合わせは、押出室５７に圧送充満されている未加硫ゴムの雰囲気内で行われるため、内円筒５５１と共に回転する３本の素線１２が撚り合わせ部分に未加硫ゴムを巻き込みながら充填してゆく。外円筒５５２を通過した９本の素線１２は、３本の素線１２の撚り合わせコードの外周に若干遅れたタイミングでさらに撚り合わされ、図８に示すように、３本の素線１２の外周に重ね合わせるように撚り合わされる。これらの撚り合わせ動作は、ゴム注入部５７ｃに圧送充満された未加硫ゴムの雰囲気中で行われるため、外円筒５５２と共に回転する９本の素線１２が未加硫ゴムを巻き込みながら進行し、よって、中心コードをなす３本の素線１２とその外周に撚り合わされる９本の素線１２との間の空隙にも未加硫ゴム１１が充填される。
【００４９】
なお、図７において、符号４０ａは、中心コードをなす３本の素線１２のためのプリフォーマで、円周方向に等間隔配置した３組の癖付けピン群からなる。また、符号４０ｂは、中心コードの外周に重ねて撚り合わされる９本の素線のためのプリフォーマで、円周方向に等間隔配置した９組の癖付けピン群からなる。癖付けピン群の各組は３本のピンからなり、第１の実施の形態について説明したように配置される。
【００５０】
（第３の実施の形態）
第３の実施の形態は、第１又は第２の実施の形態により製造されるスチールコード１０が複数本埋設されるゴムリボンを製造するリボン製造方法である。図９に示すように、このリボン製造装置８０は、図２を参照して上述したような４台のコード製造装置２０を含み、これら装置２０から送出される４本のスチールコード１０を方向変換ローラ群８１を介してリボン成形機８２の成形型ヘッド８３へ導入するように構成される。リボン成形機８２は、押出機本体８４に内蔵した例えばスクリューポンプにより未加硫ゴムを成形型ヘッド８３内へ圧送するように構成されている。図１０に示すように、成形型ヘッド８３は、ヘッド本体８３ａ内に、環状空間として形成される未加硫ゴム供給部８５と、成形ダイス８８の入口側に配置した円盤状空間としての未加硫ゴム注入部８６と、この注入部８６へ供給部８５から未加硫ゴムを圧送する複数のハブ通路８９とが形成され、出口側に前記成形ダイス８８が装着されている。成形ダイス８８は例えば、長方形断面や菱形断面等の概ね平行四辺形断面の押出成形穴８８ａが形成されている。前記方向変換ローラ群８１に沿って導入される４本のスチールコード１０は、成形型本体に所定ピッチで形成されたコード案内穴に沿って成形型本体８３ａ及びゴム注入部８６を縦断し、成形ダイス８８の押出成形穴８８ａを貫通するように走行している。
【００５１】
従って、４本のスチールコード１０は、ゴム注入部８６に圧送される未加硫ゴムと共に成形ダイス８８の押出成形穴８８ａに導入され、これにより概ね平行四辺形断面の未加硫ゴム組成内にスチールコード１０が等間隔で配置されるゴムリボン１００が押出成形穴８８ａから押し出される。
【００５２】
図１１（ａ）は、このように製造されるゴムリボン１００の一例を示し、このゴムリボン１００は、第１の実施の形態により製造される略三つ葉状のゴム被覆スチールコード１０を長方形断面の未加硫ゴム組織内に等ピッチで埋設している。コード製造装置２０を１２本素線用とする場合では、第２の実施の形態により製造される図８に示すコード１０が図１１（ｂ）に示すように断面平行四辺形の未加硫ゴム組成内に埋設配置されたゴムリボン１００が押出成形される。なお、これらゴムリボン１００は、幅が５〜１０ｍｍ前後で厚さが３ｍｍ程度の寸法である。
【００５３】
再び図９において、このように成形されたゴムリボン１００は、張力付与装置９０の巻き取りローラ９１により巻装され、この張力付与装置９０からタイヤ生産システムのボディープライ製造装置１１０に供給される。この装置１１０は、ロール１１１の回転に同期してリボン供給ヘッド１１２をトラバース送りすることにより、ロール１１１にゴムリボン１００を螺旋巻きし、この螺旋巻きをロール１１１の回転軸線と略平行に切り開いて帯状のボディープライ材１１３を製造する。このボディープライ製造装置１１０は、図１２に示すタイヤ生産システムの一部を構成している。
【００５４】
図１２に示すタイヤ生産システムの詳細は、本願出願人が先に出願した特開２００２−３０７５７０号公報に記述されているので、割愛のため詳述しない。簡単に云えば、このタイヤ生産システムは、直線状に延びる搬送ライン１２０の一方側の端に主としてボディープライから構成されるタイヤの内張り要素を生産する第１の装置群１２１を配置し、搬送ライン１２０の他方側の端に主としてベルトから構成されるタイヤの外張り要素を生産する第２の装置群１２２を配置し、外張り要素の内側に内張り要素を組み付ける組付け装置群としての第３の装置群１２３を搬送ラインの中央部に配置し、この第３装置群１２３の正面に複数の加硫機からなる第４の装置群１２４を配置して構成される。
【００５５】
上述したリボン製造装置８０は、第１の装置群１２１の前段に配置され、ボディープライを生産するためのゴムリボンを第１の装置群１２１に組み込まれるボディープライ製造装置１１０に供給する。また、同様なリボン製造装置８０は、第２の装置群１２２の前段に配置され、ベルトを生産するためのゴムリボン１００を第２の装置群１２２に組み込まれるベルト製造装置１２６に供給する。すなわち、本発明の特徴の１つは、ボディープライやベルト等のタイヤの主要構成要素をゴムリボン１００により形成し、その場合、ゴムリボン１００自体を素線１２及び未加硫ゴムからタイヤの生産と同時並行して一貫生産することにある。つまり、スチールコード１０やゴムリボン１００の中間在庫における停留を排除するのである。これにより、タイヤ生産における生産コストの低減を図ることができ、同時にゴム特性の経時変化による劣化を排除して高品質のタイヤを生産できる。特に、第１及び第２の実施形態により製造されるスチールコード１０を用いてゴムリボン１００を成形するので、スチールコード１０の素線１２間の空隙１０ａにも未加硫ゴムが充填されたゴムリボン１００が成形され、このゴムリボン１００を用いて生産されるタイヤは、スチールコード１０が錆の影響を受けにくく耐久性に優れたものとなる。
【００５６】
上述した実施の形態においては、３本の素線を撚り合せてスチールコードを製造しているが、スチールコードは複数本の素線を撚り合せて製造されるものであればよく、その数は２本、４本、５本或いはそれ以上でもよい。また、第２の実施形態では３本の素線を撚り合せた芯材コードの外周に９本の素線を重ねて撚り合せた事例を記述したが、芯材コードを構成する素線の数は複数であれば２本、４本、５本或いはそれ以上でもよく、重ねて撚り合わされる素線の数も芯材コードの外周を包囲できる数であえば、特にその本数は限定されない。
また、図８に示すスチールコード１０は、芯材コードを構成する素線の直径と芯材コードを取り囲む包囲素線の直径を同一にしているが、芯材コードのそれを太くし、包囲素線のそれを細くしてもよい。
【００５７】
さらに、図１又は図８に示すスチールコード１０を複数本互いに撚り合せてスチールコードを製造し、このスチールコードを未加硫ゴムの組織内に複数本埋設してゴムリボンを製造し、さらにこのゴムリボンを用いて空気入りタイヤを製造するようにしてもよい。
さらに、４本のスチールコードを埋設したゴムリボンの例を示したが、これ以外の複数本のスチールコードを未加硫ゴム組織内に埋設してゴムリボンを製造してもよい。
さらに、上記実施形態ではゴム被覆スチールコード１０からリボン１００を製造したが，このリボン１００を製造せずに、図１又は図８に示すゴム被覆スチールコード１０を直接ボディープライ製造装置１１０と第２の装置群１２２を構成するベルト製造装置へ供給し、これらコードによりボディープライやベルトを製造するようにしてもよい。この場合、押出機５０の送出穴５６ａの断面形状は、ゴム被覆スチールコード１０の断面形状を矩形や平行四辺形にするようにこれと対応する形状にすることが望ましい。
【図面の簡単な説明】
【図１】本発明による第１の実施の形態におけるゴム被覆コード製造方法により製造されるゴム被覆スチールコードの断面図。
【図２】本発明によるゴム被覆コード製造方法を実施するコード製造装置の概略説明図。
【図３】図２に示すコード製造装置の要部断面図。
【図４】螺旋上の癖付け処理がされたスチールコードを構成する素線の部分斜視図。
【図５】コード製造装置の押出型ヘッドに設けられる撚り維持具の斜視図。
【図６】スチールコードの疲労試験を行うコード疲労試験装置の概略説明図。
【図７】本発明による第２の実施の形態におけるゴム被覆コード製造方法を実施するコード製造装置の要部断面図。
【図８】第２の実施の形態の製造方法により製造されるゴム被覆コードの断面図。
【図９】本発明の第３の実施の形態によるゴムリボン製造方法を実施するゴムリボン製造装置の概略説明図。
【図１０】第３の実施の形態におけるリボン押出機の押出型ヘッドの水平断面図。
【図１１】（ａ）及び（ｂ）第３の実施の形態において製造されるゴムリボンの一例及び別の例の断面図。
【図１２】本発明に従ってスチールコード製造装置及びゴムリボン製造装置を組み込んだタイヤ生産システムの概略を示す説明図。
【図１３】従来のタイヤ用スチールコードの一例の断面図。
【図１４】従来のタイヤ用スチールコードの他の一例の断面図。
【図１５】従来のタイヤ用スチールコードのさらに他の一例の断面図。
【符号の説明】
１０・・・ゴム被覆スチールコード、１１・・・未加硫ゴム、１２・・・素線、１０ａ・・・撚り合わせ部分、２０・・・コード製造装置、２１・・・チューブラ型撚線機、２４・・・回転バレル、２７・・・ボビン、４０・・・プリフォーマ、５０・・・押出機、５１・・・押出型ヘッド、５５・・・撚り維持具、５５１・・・内円筒、５５２・・・外円筒、５５１a、５５２a・・・素線ガイド穴、５６・・・撚り合わせダイス、５６a・・・送出穴、５７・・・押出室（未加硫ゴムが加圧充満された雰囲気）、５７ｃ・・・ゴム注入部、６０・・・張力付与装置、７０・・・コード疲労試験装置、８０・・・リボン製造装置、８２・・・リボン成形機、８３・・・成形型ヘッド、８６・・・未加硫ゴム注入部、８８・・・成形ダイス、８８ａ・・・押出成形穴、９０・・・張力付与装置、１００・・・ゴムリボン、１１０・・・ボディープライ製造装置、１１１・・・ロール、１１２・・・リボン供給ヘッド、１１３・・・ボディープライ材、１２１・・・第１の装置群、１２２・・・第２の装置群、１２３・・・第３の装置群、１２４・・・第４の装置群。[0001]
[Technical field to which the invention belongs]
The present invention relates to a steel cord in which unvulcanized rubber is intruded into a core formed by twisting a plurality of strands. Manufacturing equipment and the same code, Rubber ribbon using the same cord and Of tires using them It relates to a manufacturing method.
[0002]
[Prior art]
The steel cord 210 used as a reinforcing material for rubber articles such as tires has a stranded wire structure, and its cross section has a 1 × 3 structure as shown in FIG. 13, for example. In this structure, the strands 212 are twisted together leaving a gap 210a at the center in a state of being in close contact with each other. Even when such a steel cord 210 is embedded in an unvulcanized rubber as a reinforcing material for a rubber article such as a tire and pressure vulcanized, the rubber hardly penetrates into the gap. For this reason, the rubber article has been used as a product with a continuous gap 210 a formed over the entire length in the longitudinal direction of the cord 210 inside the steel cord 210.
[0003]
When such a rubber article is used, when the rubber and the steel cord 210 are partially broken and moisture enters the steel cord 210 from there, the moisture travels through the gap 210a and reaches the entire length of the steel cord 210. As a result, there arises a problem that the steel cord 210 is corroded over the entire length. This corrosion, that is, the occurrence of rust, not only causes a decrease in strength due to deterioration of the steel cord 210 itself, but also inhibits the integrity of the steel cord 210 and the rubber composition to separate them, thereby improving the durability of the rubber article. Will be hindered.
[0004]
For this reason, in the invention described in Japanese Patent Laid-Open No. 55-90692, as shown in FIG. 14, the shape of the wire 212 is increased, that is, the twist is reduced, and the gap 210b is formed between the wires 212. It is provided that rubber easily penetrates between the strands 212 through the gap 210b. Further, in the invention described in Japanese Patent Laid-Open No. 56-128384, as shown in FIG. 15, the wire 212 is twisted around the thread-like rubber core core 213, and a gap is formed in the center of the cord 210 after the twisting. Seems to not exist. Furthermore, in the invention described in Japanese Patent Laid-Open No. 2001-336076 previously proposed by the present applicant, the cord once twisted is twisted back so that the rubber enters the center between the strands, and then the original twisted cord is used. I try to return it.
[0005]
In general, as a method for manufacturing a steel cord for reinforcing rubber articles, in the case of manufacturing a tire, for example, a wire drawn to a desired wire diameter is manufactured, and temporarily suspended and stocked. Thereafter, a plurality of strands are twisted with a twisting machine to produce a steel cord, and this product is temporarily held and stocked. This time, a large number of steel cords are lined up and covered with rubber by an unwinding calendar making machine to produce a large volume fabric (large volume fabric), which is temporarily held and stocked. Thereafter, the large roll is cut into a desired angle and width, and the cut pieces are joined together to produce a small roll, which is also temporarily held and stocked. Then, when necessary, the small roll is supplied to a tire molding machine to produce an unvulcanized tire. In this way, in the case of conventional tire manufacturing, the steel cord is sent to the manufacturing process several times before being supplied to the tire molding machine, and is repeatedly placed under the status of holding and stocking for each process.
[0006]
[Patent Document 1]
JP 55-90692 A
[0007]
[Patent Document 2]
JP-A-56-128384
[0008]
[Patent Document 3]
JP-A-2001-336076
[0009]
[Problems to be solved by the invention]
However, in the cord described in Japanese Patent Application Laid-Open No. 55-90692, the structure of the cord itself is unstable because the twist is sweet, and in the calendering process, for example, the process of covering the cord with rubber, the strands are tightened. There is a problem that rubber does not enter the cord center gap. In the cord described in Japanese Patent Application Laid-Open No. 56-128384, it is necessary to manufacture the thread rubber to be put into the core in advance, and to twist the strand with the thread rubber to the core, there is a difficulty in the process, the quality There is also a problem with stability. Furthermore, the cord described in JP-A-2001-336076 requires an additional step of untwisting the cord once twisted and a twisting jig.
[0010]
In addition, as described above, the steel cord is supplied to the conventional tire manufacturing method is repetitive holding / inventory, and various problems in inventory management due to an increase in inventory quantity, such as intermediate inventory costs and This increases the transportation cost to the next process, which is an obstacle to lowering the manufacturing cost of the tire.
[0011]
Therefore, the present invention provides a steel cord in which unvulcanized rubber can be reliably filled into a gap in a twisted portion of a plurality of strands by simple processing, and the unvulcanized rubber is twisted in close contact with the strands. Manufacturing equipment and It is to provide a manufacturing method.
[0012]
Another object of the present invention is that not only the unvulcanized rubber is surely filled in the gaps in the twisted portions of a plurality of strands constituting the core material, but also the outer periphery of the core wire is overlapped and twisted. Steel cord in which unvulcanized rubber is securely filled in the gap formed between the multiple strands and the outer surface of the core wire Manufacturing equipment and It is to provide a manufacturing method.
[0013]
Yet another object of the present invention is that the manufacturing process of the rubber ribbon using the steel cord includes the manufacturing process of the steel cord as a part thereof, and the manufacturing of the steel cord and the manufacturing of the rubber ribbon using the cord are performed consistently. Another object of the present invention is to provide a method for producing a rubber ribbon.
[0014]
Still another object of the present invention is to manufacture a steel cord or to manufacture a cord and a rubber ribbon using the cord. But An object of the present invention is to provide a method for producing pneumatic tires that is continuously performed as part of the production of pneumatic tires and that can eliminate the need for intermediate stock of steel cords and rubber ribbons.
[0015]
[Means for Solving the Problems]
The above-described problems and objects are solved and achieved by a solution configured as follows according to the present invention.
[0016]
That is, the invention described in claim 1 A steel cord manufacturing apparatus for producing a steel cord by twisting a plurality of strands with a tubular type twisting machine, wherein a plurality of strands fed from the tubular type twisting machine have a spiral pitch of a predetermined pitch. An extruder head for extruding unvulcanized rubber while twisting the strands fed through the preformer, and an extruder main body for supplying unvulcanized rubber under pressure to the extrusion head The extrusion head is rotatably supported concentrically with the rotation axis of the rotary barrel of the tubular twisting machine at the strand introduction section, and allows the plurality of strands to pass through in an equiangular arrangement. A twist maintaining tool formed as described above, and a sending hole for sending a twisted steel cord disposed in the cord sending section on the opposite side of the wire introduction section from the cord sending section. A twisting die, an extrusion chamber that is disposed between the tip of the twist maintaining tool and the twisting die and is filled with unvulcanized rubber by pressure, and is provided for the rotating barrel of the tubular twisted wire machine. The twist maintaining tool is driven and rotated through the plurality of strands in accordance with the rotation, so that the plurality of strands are fed out of the twisting dies in the extrusion chamber filled with the unvulcanized rubber. Twist while winding unvulcanized rubber around the hole as a base point to fill the unvulcanized rubber into the twisted part that is the center of the strands, and coat the outer periphery of the twisted steel cord with rubber To form a layer It is characterized by that.
[0017]
Claims 2 Described in invention Is A plurality of strands fed from the rotating rotating barrel of the tubular twister are swung around the feed hole of the twisting die arranged in the cord feed section of the extrusion head of the rubber extruder. In the method of manufacturing a steel cord to be twisted, a plurality of strands fed from the rotating barrel are passed through an extrusion chamber filled with unvulcanized rubber in the extrusion die head to feed the twisting dies. A twist which is a central portion of the plurality of strands is introduced into the hole and swiveled in the extrusion chamber with the feed hole of the twisting die as a base point with the rotation of the rotating barrel. Filling the mating part with unvulcanized rubber, and forming a rubber coating layer on the outer periphery of the twisted steel cord It is characterized by that.
[0019]
Claim 3 In the method of manufacturing a steel cord in which a plurality of strands are twisted by a tubular twisting machine, Radially inwardly fed from the tubular twisted wire machine A twist of at least two strands constituting the core material Similarly, the radially outer side sent from the tubular twisted wire machine Twist multiple strands of wire around the core Of rubber extrusion head Unvulcanized rubber filled with pressure With a slight time difference in twisting operation in the same extrusion chamber It is performed by shifting the timing back and forth, and at the time of twisting of the preceding at least two strands, the unfilled rubber is filled in the gaps in the twisted portions of these strands, and the subsequent step is performed. At the time of twisting a plurality of strands with respect to the outer periphery of the core material, unvulcanized rubber is filled between the core material and the strand twisted on the surface of the core material.
[0020]
Claims 4 The invention described in claim 3 In the manufacturing method described in 1., unvulcanized rubber was filled in the inner cylinder and the outer cylinder that can be freely rotated individually. Extrusion chamber A plurality of wires arranged concentrically facing the inlet side of the wire, inserted through a wire guide hole formed by penetrating at least two wires constituting the core material through the inner cylinder, and twisted around the outer periphery of the core material The strand guide holes formed by penetrating the strands of the outer cylinder into the outer cylinder are inserted, and all the strands inserted through the inner cylinder and the outer cylinder are Extrusion chamber Cross As well as this Extrusion chamber Pass through the delivery hole provided concentrically with the inner and outer cylinders on the outlet side of the inner cylinder, and insert at least the inner cylinder due to the difference in diameter between the inner and outer cylinders 2 Twisting strands of books The It is characterized by preceding the twisting of a plurality of strands inserted through the outer cylinder.
[0021]
Claim 5 The invention described in claim 2 ~ 4 A plurality of steel cords are manufactured in parallel by the manufacturing method described in any of the above, and the plurality of steel cords are aligned at intervals. For rubber ribbon production Introduced into an atmosphere filled with unvulcanized rubber in the extrusion head of a rubber extruder, and filled with multiple steel cords But Embedded in unvulcanized rubber at intervals Be done A rubber ribbon having a desired cross-sectional shape is extruded from a feed hole of an extrusion die provided on the outlet side of the atmosphere.
[0022]
And claims 6 The invention described in claim 2 ~ 4 A steel cord manufactured by the manufacturing method according to claim 1 or claim 5 The rubber ribbon manufactured by the manufacturing method described in 1 is introduced directly into the pneumatic tire production system without being stored as intermediate stock. The steel cord or A pneumatic tire is produced by manufacturing at least one of a body ply and a belt of a pneumatic tire using the rubber ribbon.
[0023]
[Operation and effect of the invention]
The invention according to claim 1 configured as described above. According to , Unvulcanized rubber in the space where multiple strands are twisted together The filling Can And unvulcanized rubber The Securely adheres to each strand Can The For this reason, In the steel cord manufactured by the manufacturing apparatus of the present invention The rust resistance of steel cords made by twisting multiple strands is improved without the entry of gas or liquid that induces rust such as water vapor or water into the twisted portion between strands, and the steel cord itself The lifetime in the function can be extended.
Also, On the surface other than the twisted part of multiple strands Even with rubber coating, this Rubber coating By Rust-proof these wires from the outside be able to . This Manufactured by the manufacturing apparatus of the present invention The rust prevention of the steel cord is further ensured, and the life of the steel cord itself is extended. The Further promotion Can The
[0026]
Claims configured as above 2 In the invention described in 1, the tubular type twisted wire machine As the rotating barrel of the Multiple strands twisted together By swirling in an extrusion chamber filled with unvulcanized rubber by pressure. Since the unvulcanized rubber that can be bonded to the strands is wrapped and filled with the strands at the points where the strands are twisted together, the unvulcanized rubber can be reliably filled in the twisted portions between the strands. It is possible to provide a method of manufacturing a steel cord that can securely attach a vulcanized rubber to a strand, that is easy to operate, has a low product yield, and can reduce manufacturing costs.
Also, Claim 2 In the invention described in 1, the unvulcanized rubber was filled with pressure by twisting the strands. Extrusion chamber In the process of twisting the strands, the pressurized unvulcanized rubber penetrates and fills the twisted part while being wound around the strands, and the strands of strands are twisted together. The non-vulcanized rubber is reliably coated on the surface other than the portion. Thereby, the steel cord excellent in rust prevention property can be manufactured by simple processing operation.
[0027]
Claims configured as above 3 In the invention described in 1, the unvulcanized rubber was filled with pressure. Same extrusion chamber so, Radially inward While twisting at least two strands constituting the core material, With a slight time difference from this twisting, On the outer periphery of the core material twisted in this way Radially outward Since a plurality of strands are further twisted together, unvulcanized rubber is caught in the twisted portion of the core material to ensure filling, and the core material and the plurality of strands twisted to the core material are twisted together. Unvulcanized rubber is reliably filled between the wires, and the surfaces other than the twisted portions of all the strands are reliably covered with unvulcanized rubber. As a result, the strength is further enhanced and rust prevention is achieved. Steel cords with excellent properties and durability can be manufactured.
[0028]
Claims configured as above 4 In the invention described in 1, the unvulcanized rubber was filled with pressure. Extrusion chamber Before introducing into the inside, at least two strands constituting the core material are passed through the inner cylinder, and another plurality of strands twisted around the outer periphery of the core material are arranged concentrically with the inner cylinder. Since the cylinders are penetrated, the twisting action of the strands that penetrate the inner cylinder and the twisting action of the strands that penetrate the outer cylinder can be made to have a time difference using these concentric cylinders. It has become possible. As a result, after a core material in which at least two strands are twisted together is reliably formed, a plurality of strands can be twisted on the surface of the core material, and unvulcanized to the twisted portion of the core material The rubber can be filled reliably, and the gap between the core material and the strand twisted on the surface of the core material can be reliably filled with unvulcanized rubber, and the surface other than the twisted portion of the strand is not filled. A steel cord coated with vulcanized rubber can be produced.
[0029]
Claims configured as above 5 In the invention described in claim 1, 2 ~ 4 A plurality of steel cords manufactured according to any of the inventions are aligned at intervals For rubber ribbon production These steel cords are embedded from the feed hole of the desired cross-sectional shape of the extrusion die introduced into the atmosphere filled with unvulcanized rubber in the extrusion die head of the extruder and provided on the outlet side of the atmosphere Since the unvulcanized rubber is extruded in a state in which the rubber cord is excellent, it is possible to manufacture a rubber ribbon having excellent durability in which a plurality of steel cords having excellent rust prevention properties are embedded at intervals.
Claims configured as above 6 In the invention described in claim 1, 2 ~ 5 The steel cord or rubber ribbon manufactured by the invention according to any one of the above items is directly introduced into a pneumatic tire production system without being stored as an intermediate stock, and a tire is formed from the steel cord or rubber ribbon as a material. Since at least one of the ply and the belt is manufactured, a low-cost method for producing tires that does not require steel cords and rubber ribbons to be stored as intermediate stock is realized, and the steel cord is filled with unvulcanized rubber. Production of tires with stable quality and reliable anticorrosion treatment of steel cords with little change over time of unvulcanized rubber from the time of rubber ribbon production to the time of vulcanization of green tires A method is realized.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a rubber-coated steel cord and a method for producing the same according to the present invention that can be used for reinforcing rubber articles will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a steel cord 10 manufactured according to a first embodiment of the present invention. The steel cord 10 is configured as a 1 × 3 structure. The cord 10 is twisted in a state in which the three strands 12 are circumscribed with each other so that the centers of the strands are located at the three corners of a virtual equilateral triangle having a length approximately matching the diameter of the strand 12, It is covered with raw rubber, that is, unvulcanized rubber 11. The central portion 10a of the cord 10 defined by the external contacts between the strands 12 is filled with unvulcanized rubber, whereby each strand 12 is twisted between the strands 12 that coincide with the central portion 10a of the cord 10. Substantially all the outer surfaces including the portion are covered with the unvulcanized rubber 11.
[0031]
The strand 12 is made of a steel material and has a wire diameter of 0.25 mm as an example, but it goes without saying that other materials and strands having other wire diameters can be adopted. In the example shown in FIG. 1, the outer periphery of the cord 10 is formed in a substantially three-leaf shape. Since the outer peripheral shape of the cord 10 is specified by the cross-sectional shape of the delivery hole of the twisting die, which will be described later, by changing the cross-sectional shape of the delivery hole of the die, in addition to the substantially three-leaf shape, for example, Other shapes, such as squares, are possible. Further, the cord 10 can employ a single twisted cord having a 1x4 structure in which four strands 12 are twisted, a 1x5 structure in which five strands 12 are twisted, or other structures such as a bundle twisted cord. For convenience of explanation, the following explanation is made with a steel cord 10 adopting a 1 × 3 structure as a cord structure as a representative example.
[0032]
FIG. 2 shows a cord manufacturing apparatus 20 for carrying out the steel cord manufacturing method according to the present invention. The cord manufacturing apparatus 20 includes a tubular stranded wire machine 21, a preformer 40, a rubber extruder 50, and a tension applying device 60. The tubular stranded wire machine 21 includes a rotating barrel 24 that is rotatably supported by a main body 22 via a bearing 23, and an electric motor 26 that rotationally drives the rotating barrel 24 via a belt / pulley transmission mechanism 25. In the rotating barrel 24, three bobbins 27 each wound with a steel strand 12 are arranged in the longitudinal direction. The number of bobbins 27 corresponds to the number of strands 12 in the code structure. By applying a constant winding tension by the tension applying device 60, the rotating barrel 24 provides the steel strands 12 fed from the three bobbins 27 at intervals of 120 degrees on the outer peripheral edge of the front end surface. It sends out from the three strand sending holes 33.
[0033]
A strand guide plate 41 and a preformer 40 are provided on the front end surface of the rotating barrel 24 so as to rotate integrally with the rotating barrel 24. The preformer 40 brazes a spiral with a predetermined pitch for each strand 12 to facilitate twisting. The rubber extruder 50 includes an extrusion die head 51 that extrudes rubber while twisting the strands 12 and an extruder main body 52 that pressurizes and supplies unvulcanized rubber to the head 51. The tension applying device 60 rotates the winding drum 61 at a predetermined speed, positively winds the rubber-coated cord 10 fed out from the extrusion head 51, and the strand 12 passing through the preformer 40 and the extrusion head 51. A predetermined tension is applied to each. The rubber covered cord 10 fed out from the take-up drum 61 is also arranged at an equal pitch, for example, at intervals of several millimeters, such as about 4 to 8, including other plural rubber coated cords manufactured in parallel. The cords are assembled as a group of codes and sent to a rubber extruder for ribbon forming, as will be described in detail in a third embodiment to be described later.
[0034]
FIG. 3 is an enlarged detail view of a portion surrounded by a two-dot chain line in FIG. A plurality of (three in this embodiment) bobbin storage chambers are defined in the longitudinal direction of the rotary barrel 24, and a cradle 28 is paired in the front and rear on the rotational axis of the rotary barrel 24 in each of the storage chambers. The bearing member 29 is supported at both ends so as to be swingable. On the cradle 28, a bearing rod 30 is erected so as to extend in the diameter direction of the bearing member 29, and a bobbin 27 around which the wire 12 is wound is rotatably supported around the bearing rod 30 by the bearing rod 30. Yes. The strand 12 fed out from each bobbin 27 runs on a guide roller 31 that is rotatably supported in parallel with the bobbin 27, passes through the through hole of the front bearing member 29, and two or more direction change guide rollers. 32 is guided radially outward from the axial center of the rotating barrel 24, guided from there in the longitudinal direction of the rotating barrel 24, and sent to the outside through a delivery port 33 that opens at the front end face of the rotating barrel 24.
[0035]
A support rod 42 projects from the center of the front end surface of the rotating barrel 24, and the wire guide plate 41 and the preformer 40 are provided on the support rod 42. The guide plate 41 has a guide hole opened at an angular position corresponding to the delivery port 33, and guides the three strands 12 through the guide holes. The pre-former 40 is constituted by three sets of spiral brazing means each composed of three brazing pins 45 protruding in the radial direction. The two front and rear pins of each set of brazing pins 45 are arranged at the same angular phase as the corresponding delivery holes 33, while the middle one is arranged with a phase different from the two front and rear. As a result, each strand 12 is bent into a V shape when traveling along the corresponding set of three brazing pins 45, passes through the brazing pins 45, and then spirals as shown in FIG. The plastic deformation properties appear periodically at a predetermined pitch.
[0036]
The three strands 12 that have passed through the preformer 40 are introduced into the extrusion die head 51 of the rubber extruder 50 while gathering toward the rotation axis of the rotary barrel 24. The extrusion die head 51 is opposite to the extrusion die main body 53, a twist maintaining tool 55 that is rotatably supported via a bearing member 54 concentrically with the rotation axis of the rotary barrel 24 in the strand introduction portion, and the strand introduction portion. It comprises a twisting die 56 disposed in the cord sending section on the side, and an extrusion chamber 57 disposed between the tip of the twist maintaining tool 55 and the die 56. As shown in FIG. 5, the twist maintaining tool 55 includes a flange portion 55a, a bearing portion 55b, and a spline portion 55c. On the outer periphery of the spline portion 55c, three separation passage grooves 55m are formed in the longitudinal direction at an equal angle (120 degrees) corresponding to the number of strands 12 to be twisted. The separation passage groove 55m is formed as a semicircular groove corresponding to the cross-sectional area of the strand 12. Separation passage holes 55h having a slightly larger cross-section than the cross-sectional area of the wire 12 are communicated with the separation passage groove 55m in the bearing portion 55b and the flange portion 55a. The three strands 12 introduced into the extrusion die 15 are passed through the three separation passage holes 55h of the twist maintaining tool 55, and then guided to the separation passage groove 55m and guided to the rubber injection portion 57c. From there, it passes through the die 56. The main body 52 of the extruder 50 pumps unvulcanized rubber to the ring-shaped supply part 57a by, for example, a screw pump, and unvulcanizes from the supply part 57a to the disk-shaped rubber injection part 57c through a plurality of hub passages 57b. Inject rubber. That is, the extrusion chamber 57 forms an atmosphere in which unvulcanized rubber is pumped and filled, and the strands 12 are twisted in this atmosphere.
[0037]
As a result, unvulcanized rubber is filled while being wound by the strands 12 into the gaps in the axial center of the cord 10 composed of the three strands 12 passing through the rubber injection portion 57c while being twisted, and simultaneously twisted. Unvulcanized rubber is also coated on the outer peripheral surface of the combined cord 10. The cross-sectional area of the cord delivery hole 56a of the die 56 is formed in a substantially three-leaf shape that is slightly larger than the cross-section of the cord 10, and the twisted cord 10 is coated with unvulcanized rubber on the outer peripheral surface from the delivery hole 56a. Is sent out.
[0038]
Next, the operation of the first embodiment configured as described above will be described.
In response to the manufacturing start command, the rotating barrel 24 is rotated by the motor 26 via the pulley / belt transmission mechanism 25. At the same time, the take-up drum 61 of the tension applying device 60 is rotated, and the rubber extruder 50 is operated to pump unvulcanized rubber to the extrusion die head 51. The winding drum 61 and the rotating barrel 24 of the tension applying device 60 are rotated at a predetermined speed so as to maintain a predetermined speed ratio. This speed can be set arbitrarily, and the twist pitch of the wire 12 can be set to a value such as 14 mm or 50 mm. In order to adjust the rotation ratio, normally, the twisting pitch of the cord 10 can be changed by changing the winding speed of the winding drum 61 while keeping the rotation speed of the rotating barrel 24 constant. For this reason, the motor 62 that drives the take-up drum 61 uses a variable speed motor such as a servo motor. If necessary, one or both of the motor 26 for rotationally driving the barrel 24 and the motor 62 for rotationally driving the take-up drum 61 may be constituted by a servo motor.
[0039]
By controlling the rotation ratio, the rotary barrel 24 rotates integrally with the wire guide plate 41 and the preformer 40 at a predetermined angle while the wire 12 is fed out from the three bobbins 27 mounted on the rotary barrel 24 by a predetermined length. Then, the twist maintaining tool 55 that passes through the strand 12 is rotated so as to follow the rotation of the rotating barrel 24 via the strand 12. Of dice 56 Send Hole 56 a Prevents the three strands 12 from rotating, so that the three strands 12 guided by the separation passage groove 55m of the spline portion 55c of the twist maintaining tool 55 are Send Hole 56 a Based on Times And twisted together. When this twisting operation is performed, the three strands 12 that have passed through the twist maintaining tool 55 are swung in an extrusion chamber 57 that forms an atmosphere filled with unvulcanized rubber, and are unvulcanized rubber. The rubber injection portion 57c is filled with unvulcanized rubber in the twisted portion that is the central portion between them. When the cord 10 is formed by twisting the three strands 12 until they are in contact with each other, the center of the cord 10 is completely filled with unvulcanized rubber.
[0040]
That is, while the strands 12 are transported through the separation passing hole 55h and the separation passage groove 55m of the twist maintaining tool 55 to be rotated, the strands 12 are maintained in a state before being twisted together, and are predetermined between the three strands 12. Is maintained. In this state, the unvulcanized rubber enters the central gap of the three strands 12 by being twisted while passing through the rubber injection portion 57c of the rubber extruder 50. In this way, a steel cord 10 having a twisted structure in which unvulcanized rubber is used as a core and three strands are arranged on the outer periphery of the core is manufactured. Furthermore, since the die 56 is disposed on the exit side of the extrusion die head 51 of the extruder 50, the die 56 is transferred through the die 56 while being twisted by the twisting stress of the strands 12 maintained in parallel. Thus, the rubber coating layer 11 is also formed on the outer periphery of the twisted cord 10. As a result, the cord 10 is manufactured in which three strands 12 are arranged around the unvulcanized rubber as a core and the outer periphery thereof is coated with the compounded rubber.
[0041]
Example 1:
A twisted cord having a twist pitch of 14 mm having a 1 × 3 structure was manufactured as Example 1 using a strand having a wire diameter of 0.25 mm by the manufacturing method of the above embodiment.
Example 2:
A twisted cord with a twist pitch of 50 mm having a 1 × 3 structure was manufactured as Example 2 using a strand having a wire diameter of 0.25 mm by the manufacturing method of the above embodiment. Normally, the twist pitch is used in a range not exceeding 100 times the linear pitch, whereas the twist pitch of 50 mm in Example 2 is a long twist pitch corresponding to 200 times the strand diameter (d = 0.25 mm). It is.
[0042]
By increasing the twist pitch in this manner, the twisting speed is increased, the production efficiency of the stranded wire cord 10 is improved, and rubber penetration during the twisting operation is facilitated at the same time. Therefore, the twist maintaining tool 55 becomes unnecessary, and the manufacturing cost can be reduced. In this viewpoint, a preferable twist pitch range is 100 to 300 times the diameter of the strand 12.
Comparative Example 1:
A twisted cord having a twist pitch of 14 mm having a 1 × 3 structure was manufactured as a comparative example 1 by using a strand having a wire diameter of 0.25 mm by a conventional method. The comparative example 1 has a cross-sectional structure shown in FIG. 13, and the cord center is not filled with unvulcanized rubber.
Comparative Example 2:
A twisted cord having a twist pitch of 14 mm having a 1 × 3 structure was manufactured as Comparative Example 2 using a strand having a wire diameter of 0.25 mm by a conventional method disclosed in Japanese Patent Application Laid-Open No. 55-90652.
For these Comparative Example 1, Comparative Example 2, Example 1 and Example 2, the rubber penetration rate and cord fatigue were tested, and the results were as shown in Table 1 below.
[0043]
[Table 1]

The following methods were employed as test methods for rubber penetration rate and cord fatigue.
Rubber penetration rate: Pneumatic radial tires are produced by the tire production method described later using each of four types of cords having structures, wire diameters and twist pitches defined in the comparative examples and examples in Table 1. did. The steel cord was taken out from each of the four types of tires with rubber adhered. After removing the rubber from the surface of the steel cord with rubber, carefully remove one, two and the strands, and observe the above sample of about 10 cm in length to see how long the rubber is completely filled in the gap. Was measured. The ratio of the portion filled with rubber to the total length of the sample was defined as the rubber penetration rate.
[0044]
Cord fatigue property: A cord fatigue test apparatus 70 shown in FIG. 6 is used. Three rollers 73 are supported on a slider 72 that moves horizontally on the pilot bar 71 so as to be freely rotatable, and a vulcanized rubber-coated steel cord sample is wound between the three rollers 73 and one end of the sample is also wound. And the other end is tensioned with a weight 74 having a predetermined weight. The slider 72 was reciprocated left and right by a predetermined stroke L, and the number of reciprocations until the cord was cut was obtained. In the evaluation, the relative evaluation of Comparative Example 2 and Examples 1 and 2 when Comparative Example 1 is set to 100 is indicated by an index.
[0045]
From these test results, it was confirmed that the rubber penetration rate and cord fatigue were related, and Example 1 with the best rubber penetration rate was 30% more durable than Comparative Example 1. Moreover, it was confirmed that Example 2 achieves about 10% higher durability than Comparative Example 2 without a twisting maintenance tool. From these tests, it was confirmed that both Examples 1 and 2 were superior in durability to Comparative Examples 1 and 2.
[0046]
(Second Embodiment)
FIG. 7 is an enlarged view of a main part in the second embodiment of the code manufacturing method. The rotating barrel 24 has twelve bobbins, and the strands 12 are respectively inserted from three equally spaced delivery holes on the small-diameter pitch circle provided on the front end face and nine delivery holes on the large-diameter pitch circle. It is sent out to be collected on the rotation axis. The arrangement relationship of the nine delivery holes on the large-diameter pitch circle is determined by the relationship between the rotation speed of the barrel 24 and the winding speed of the drum 61 so as to obtain a twisted structure as shown in FIG. The extrusion head 51 of the extruder 50 has a twist maintaining tool 55 arranged on the rotation axis of the rotating barrel 24. The twist maintaining tool 55 includes two inner and outer cylinders 551 and 552 that are concentrically arranged. The outer cylinder 552 is rotatably supported via a bearing member 554, and the inner hole is inserted into the inner hole of the outer cylinder 552 via a bearing member 553. A cylinder 551 is rotatably supported. As in the case shown in FIG. 5, the inner cylinder 551 is formed with three strand guide holes 551 a that are arranged at regular intervals (120 degrees) in the circumferential direction, and the outer cylinder 552 has a circumferential direction and the like. Nine strand guide holes 552a arranged at intervals (40 degrees) are formed through. The strands 12 fed out from the three feed holes spaced 120 degrees from the outer peripheral edge of the front end surface of the rotating barrel 24 are introduced into the three strand guide holes 551a of the inner cylinder 551, penetrate through the inner cylinder 551, From there, it is introduced into the cord sending hole 56 a of the twisting die 56. The strands 12 fed out from the remaining nine delivery holes at the outer circumferential edge of the front end surface of the rotating barrel 24 are introduced into the nine strand guide holes 552a formed at intervals of 40 degrees in the circumferential direction of the outer cylinder 552. Then, after passing through these guide holes 552a, they are introduced into the code sending hole 56a of the die 56.
[0047]
The rubber supply portion 57a is a disk that accommodates the rear end portion of the twist maintaining tool 55 so that the rear end portions of the inner and outer cylinders 551 and 552 of the twist maintaining tool 55 face the atmosphere filled with unvulcanized rubber by pressure. And is formed so that unvulcanized rubber is supplied from a screw pump (not shown). This rubber supply portion 57a is unvulcanized to a rubber injection portion 57c that also forms a disk-like space via a tapered passage 57b formed as a tapered cylindrical space allowing rotation of the strand 12 around the axis of the rotating barrel 24. Connected to pump rubber. The steel cord 10 taken up by the take-up roll 61 of the tension applying device 60 is sent out from the cord sending hole 56a of the die 56.
[0048]
That is, when the rotating barrel 24 is rotated at a predetermined speed synchronized with the winding speed of the steel cord 10 by the tension applying device 60, the inner cylinder 551 and the outer cylinder 552 are rotated together under the tension of the strand 12. The In this case, the strands 12 that have passed through the cylinders 551 and 552 are twisted together because they turn toward the cord sending hole 56a of the die 56 while turning around the cord sending hole 56a. The three strands 12 that are the core material that has passed through the inner cylinder 551 are twisted faster than the nine strands 12 that have passed through the outer cylinder 552 having a large radial discrepancy because the radial discrepancies are small. The That is, the inner three strands due to the difference in diameter between the inner cylinder 551 and the outer cylinder 552, more precisely, the difference in diameter between the circle where the strand guide hole 551a is placed and the circle where the strand guide hole 552a is placed. The 12 twisting operations and the outer nine strands 12 are performed at different timings with a slight time difference. This twisting is Out Since the process is performed in an atmosphere of unvulcanized rubber that is pressure-filled in the chamber 57, the three strands 12 that rotate together with the inner cylinder 551 are filled while the unvulcanized rubber is wound around the twisted portion. The nine strands 12 that have passed through the outer cylinder 552 are further twisted at a slightly delayed timing on the outer periphery of the twisted cord of the three strands 12, and as shown in FIG. It is twisted so as to overlap the outer periphery. Since these twisting operations are performed in an atmosphere of unvulcanized rubber that is pumped and filled in the rubber injection portion 57c, the nine strands 12 that rotate together with the outer cylinder 552 proceed while entraining the unvulcanized rubber. Therefore, the unvulcanized rubber 11 is also filled in the gap between the three strands 12 forming the center cord and the nine strands 12 twisted around the outer periphery thereof.
[0049]
In FIG. 7, reference numeral 40a denotes a preformer for the three strands 12 forming the center code, and includes three groups of brazing pins arranged at equal intervals in the circumferential direction. Reference numeral 40b denotes a preformer for nine strands that are laid over and twisted on the outer periphery of the center cord, and includes nine groups of brazing pins arranged at equal intervals in the circumferential direction. Each set of brazing pin groups consists of three pins and is arranged as described in the first embodiment.
[0050]
(Third embodiment)
The third embodiment is a ribbon manufacturing method for manufacturing a rubber ribbon in which a plurality of steel cords 10 manufactured according to the first or second embodiment are embedded. As shown in FIG. 9, the ribbon manufacturing apparatus 80 includes four cord manufacturing apparatuses 20 as described above with reference to FIG. 2, and changes the direction of the four steel cords 10 delivered from these apparatuses 20. It is configured to be introduced into the forming die head 83 of the ribbon forming machine 82 through the roller group 81. The ribbon molding machine 82 is configured to pressure-feed unvulcanized rubber into the mold head 83 by, for example, a screw pump built in the extruder main body 84. As shown in FIG. 10, the mold head 83 includes an unvulcanized rubber supply portion 85 formed as an annular space in the head body 83 a and an unvulcanized disk space disposed on the inlet side of the molding die 88. A vulcanized rubber injection portion 86 and a plurality of hub passages 89 for pumping unvulcanized rubber from the supply portion 85 to the injection portion 86 are formed, and the molding die 88 is mounted on the outlet side. The forming die 88 is formed with an extrusion hole 88a having a substantially parallelogram-shaped cross section such as a rectangular cross section or a rhombus cross section. The four steel cords 10 introduced along the direction changing roller group 81 are formed by longitudinally cutting the molding die body 83a and the rubber injection portion 86 along cord guide holes formed at a predetermined pitch in the molding die body. The die 88 runs so as to pass through the extrusion hole 88a.
[0051]
Accordingly, the four steel cords 10 are introduced into the extrusion hole 88a of the molding die 88 together with the unvulcanized rubber fed to the rubber injecting portion 86, and thereby, within the unvulcanized rubber composition having a substantially parallelogram cross section. The rubber ribbon 100 in which the steel cords 10 are arranged at equal intervals is extruded from the extrusion hole 88a.
[0052]
FIG. 11 (a) shows an example of the rubber ribbon 100 manufactured in this way. This rubber ribbon 100 is formed by adding the substantially three-leaf rubber coated steel cord 10 manufactured according to the first embodiment to a rectangular cross section. It is embedded at an equal pitch in the rubber rubber structure. When the cord manufacturing apparatus 20 is used for 12 strands, the cord 10 shown in FIG. 8 manufactured according to the second embodiment is an unvulcanized rubber having a parallelogram cross section as shown in FIG. A rubber ribbon 100 embedded in the composition is extruded. These rubber ribbons 100 have a width of about 5 to 10 mm and a thickness of about 3 mm.
[0053]
In FIG. 9 again, the rubber ribbon 100 formed in this way is wound around the take-up roller 91 of the tension applying device 90 and supplied from the tension applying device 90 to the body ply manufacturing device 110 of the tire production system. The apparatus 110 traverses the ribbon supply head 112 in synchronization with the rotation of the roll 111 to spirally wind the rubber ribbon 100 around the roll 111, and the spiral winding is cut open substantially parallel to the rotation axis of the roll 111 to form a belt-like shape. The body ply material 113 is manufactured. This body ply manufacturing apparatus 110 constitutes a part of the tire production system shown in FIG.
[0054]
Details of the tire production system shown in FIG. 12 are described in Japanese Patent Application Laid-Open No. 2002-307570 filed earlier by the applicant of the present application, and will not be described in detail for the sake of brevity. In short, the tire production system includes a first device group 121 that produces tire lining elements mainly composed of body plies at one end of a linearly extending conveyance line 120, and the conveyance line. A second device group 122 for producing a tire outer element mainly composed of a belt is arranged at the other end of 120, and a third as an assembling device group for assembling the inner liner element inside the outer element. The device group 123 is arranged at the center of the conveying line, and a fourth device group 124 composed of a plurality of vulcanizers is arranged in front of the third device group 123.
[0055]
The ribbon manufacturing apparatus 80 described above is disposed in the front stage of the first apparatus group 121 and supplies a rubber ribbon for producing body plies to the body ply manufacturing apparatus 110 incorporated in the first apparatus group 121. A similar ribbon manufacturing apparatus 80 is arranged in front of the second apparatus group 122 and supplies a rubber ribbon 100 for producing a belt to a belt manufacturing apparatus 126 incorporated in the second apparatus group 122. That is, one of the features of the present invention is that the main components of the tire such as a body ply and a belt are formed by the rubber ribbon 100, and in this case, the rubber ribbon 100 itself is formed simultaneously with the production of the tire from the wire 12 and the unvulcanized rubber. It is to produce consistently in parallel. That is, the stay in the intermediate stock of the steel cord 10 and the rubber ribbon 100 is eliminated. Thereby, it is possible to reduce the production cost in the tire production, and at the same time, it is possible to produce a high-quality tire by eliminating deterioration due to a change in rubber characteristics with time. In particular, since the rubber ribbon 100 is formed using the steel cord 10 manufactured according to the first and second embodiments, the rubber ribbon 100 in which the gap 10a between the strands 12 of the steel cord 10 is also filled with unvulcanized rubber. In the tire produced using this rubber ribbon 100, the steel cord 10 is less susceptible to rust and has excellent durability.
[0056]
In the above-described embodiment, the steel cord is manufactured by twisting three strands, but the steel cord may be manufactured by twisting a plurality of strands, and the number is as follows. Two, four, five or more may be used. In the second embodiment, an example in which nine strands are overlapped and twisted on the outer periphery of a core cord formed by twisting three strands is described. The number of strands constituting the core cord The number of wires may be two, four, five, or more as long as the number of strands is not limited as long as the number of strands that are laid and twisted can surround the outer periphery of the core cord.
Further, the steel cord 10 shown in FIG. 8 has the same diameter as the wire constituting the core material cord and the diameter of the surrounding wire surrounding the core material cord. You may make it thin on the line.
[0057]
Further, a plurality of steel cords 10 shown in FIG. 1 or FIG. 8 are twisted together to produce a steel cord, and a plurality of steel cords are embedded in the structure of unvulcanized rubber to produce a rubber ribbon. You may make it manufacture a pneumatic tire using.
Further, although an example of a rubber ribbon in which four steel cords are embedded has been shown, a rubber ribbon may be manufactured by embedding a plurality of other steel cords in an unvulcanized rubber structure.
Further, in the above embodiment, the ribbon 100 is manufactured from the rubber-coated steel cord 10. However, without manufacturing the ribbon 100, the rubber-coated steel cord 10 shown in FIG. The body ply and the belt may be manufactured by using the cords supplied to the belt manufacturing apparatus constituting the apparatus group 122. In this case, the delivery hole 56 of the extruder 50 a The cross-sectional shape of the rubber-coated steel cord 10 is preferably a shape corresponding to the rectangular cross-sectional shape so that the cross-sectional shape of the rubber-coated steel cord 10 is a rectangle or a parallelogram.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a rubber-coated steel cord manufactured by a rubber-coated cord manufacturing method according to a first embodiment of the present invention.
FIG. 2 is a schematic explanatory view of a cord manufacturing apparatus for carrying out the rubber-coated cord manufacturing method according to the present invention.
3 is a cross-sectional view of a main part of the cord manufacturing apparatus shown in FIG.
FIG. 4 is a partial perspective view of a wire constituting a steel cord that has been brazed on a spiral.
FIG. 5 is a perspective view of a twist maintaining tool provided in the extrusion head of the cord manufacturing apparatus.
FIG. 6 is a schematic explanatory diagram of a cord fatigue test apparatus for conducting a fatigue test of a steel cord.
FIG. 7 is a cross-sectional view of an essential part of a cord manufacturing apparatus for performing a rubber-coated cord manufacturing method according to a second embodiment of the present invention.
FIG. 8 is a cross-sectional view of a rubber-coated cord manufactured by the manufacturing method of the second embodiment.
FIG. 9 is a schematic explanatory view of a rubber ribbon manufacturing apparatus for performing a rubber ribbon manufacturing method according to a third embodiment of the present invention.
FIG. 10 is a horizontal sectional view of an extrusion die head of a ribbon extruder according to a third embodiment.
11A and 11B are cross-sectional views of one example and another example of a rubber ribbon manufactured in the third embodiment.
FIG. 12 is an explanatory view schematically showing a tire production system incorporating a steel cord manufacturing apparatus and a rubber ribbon manufacturing apparatus according to the present invention.
FIG. 13 is a cross-sectional view of an example of a conventional steel cord for tires.
FIG. 14 is a cross-sectional view of another example of a conventional steel cord for tires.
FIG. 15 is a cross-sectional view of still another example of a conventional steel cord for tires.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Rubber-coated steel cord, 11 ... Unvulcanized rubber, 12 ... Elementary wire, 10a ... Twist part, 20 ... Cord manufacturing apparatus, 21 ... Tubular type twisted wire machine , 24 ... rotating barrel, 27 ... bobbin, 40 ... preformer, 50 ... extruder, 51 ... extrusion head, 55 ... twist retainer, 551 ... inner cylinder 552 ... outer cylinder, 551a, 552a ... strand guide hole, 56 ... twisting die, 56a ... delivery hole, 57 ... extrusion chamber (unvulcanized rubber is filled with pressure) 57c ... rubber injection part, 60 ... tension applying device, 70 ... cord fatigue testing device, 80 ... ribbon manufacturing device, 82 ... ribbon forming machine, 83 ... molding Mold head, 86 ... unvulcanized rubber injection part, 88 ... molding die, 88 ... Extrusion hole, 90 ... Tension applying device, 100 ... Rubber ribbon, 110 ... Body ply manufacturing device, 111 ... Roll, 112 ... Ribbon supply head, 113 ... Body ply 121, first device group, 122, second device group, 123, third device group, 124, fourth device group.

Claims (6)

A steel cord manufacturing apparatus for producing a steel cord by twisting a plurality of strands with a tubular type twisting machine, wherein a plurality of strands fed from the tubular type twisting machine have a spiral pitch of a predetermined pitch. An extruder head for extruding unvulcanized rubber while twisting the strands fed through the preformer, and an extruder main body for supplying unvulcanized rubber under pressure to the extrusion head The extrusion head is rotatably supported concentrically with the rotation axis of the rotary barrel of the tubular twisting machine at the strand introduction section, and allows the plurality of strands to pass through in an equiangular arrangement. A twist maintaining tool formed as described above, and a sending hole for sending a twisted steel cord disposed in the cord sending section on the opposite side of the wire introduction section from the cord sending section. A twisting die, an extrusion chamber that is disposed between the tip of the twist maintaining tool and the twisting die and is filled with unvulcanized rubber by pressure, and is provided for the rotating barrel of the tubular twisted wire machine. The twist maintaining tool is driven and rotated through the plurality of strands in accordance with the rotation, so that the plurality of strands are fed out of the twisting dies in the extrusion chamber filled with the unvulcanized rubber. Twist while winding unvulcanized rubber around the hole as a base point to fill the unvulcanized rubber into the twisted part that is the center of the strands, and coat the outer periphery of the twisted steel cord with rubber An apparatus for manufacturing a steel cord, wherein a layer is formed. A plurality of strands fed from the rotating rotating barrel of the tubular twister are swung around the feed hole of the twisting die arranged in the cord feed section of the extrusion head of the rubber extruder. In the method of manufacturing a steel cord to be twisted, a plurality of strands fed from the rotating barrel are passed through an extrusion chamber filled with unvulcanized rubber in the extrusion die head to feed the twisting dies. A twist which is a central portion of the plurality of strands is introduced into the hole and swiveled in the extrusion chamber with the feed hole of the twisting die as a base point with the rotation of the rotating barrel. The steel core is characterized in that a rubber coating layer is formed on the outer periphery of the twisted steel cord while filling the unsealed rubber with the unwrapped rubber in the mating portion. The method of production. In the method of manufacturing a steel cord in which a plurality of strands are twisted by a tubular twisting machine, at least two strands constituting a radially inner core material sent from the tubular twisting machine are twisted together Similarly, twisting of a plurality of strands with respect to the outer periphery of the core material on the radially outer side sent from the tubular twisting machine is performed in the same extrusion chamber filled with the unvulcanized rubber of the rubber extrusion head. The twisting operation is performed with a slight time lag and the timing is shifted back and forth, and at the time of twisting of the at least two strands, the unvulcanized rubber is filled in the gaps in the twisted portion of the strands. In addition, during the subsequent twisting of a plurality of strands with respect to the outer periphery of the core material, there is no addition between the core material and the strands twisted on the surface of the core material. Method for producing a steel cord, characterized in that filling to involve rubber. 4. The manufacturing method according to claim 3 , wherein an inner cylinder and an outer cylinder that can freely rotate are arranged concentrically facing an inlet side of the extrusion chamber filled with unvulcanized rubber under pressure, and the core material A plurality of strands that are twisted around the outer periphery of the core member are inserted through the outer cylinder, and at least two strands constituting the core are inserted through the inner cylinder. the wire guide hole is inserted and passes through the inner cylinder and the delivery hole provided in the inner and outer cylinder concentric to the outlet side of the extrusion chamber with all of the wires inserted through the outer cylinder to traverse said extrusion chamber And twisting of at least two strands passing through the inner cylinder due to a difference in diameter between the inner and outer cylinders is performed prior to twisting of a plurality of strands passing through the outer cylinder. A method for producing a steel cord. A plurality of steel cords are manufactured in parallel by the manufacturing method according to any one of claims 2 to 4 , and the plurality of steel cords are aligned at intervals to be extruded by a rubber extruder for manufacturing a rubber ribbon. A rubber ribbon having a desired cross-sectional shape is introduced into the atmosphere in which the unvulcanized rubber in the mold head is pressurized and filled, and the plurality of steel cords are embedded in the unvulcanized rubber at intervals. A method for producing a rubber ribbon, characterized by extruding from a feed hole of an extrusion die provided on the outlet side. The steel cord manufactured by the manufacturing method according to any one of claims 2 to 4 or the rubber ribbon manufactured by the manufacturing method according to claim 5 is directly introduced into a pneumatic tire production system without being stored as intermediate stock. The production system is characterized in that the pneumatic tire is produced by producing at least one of a body ply and a belt of the pneumatic tire using the steel cord or the rubber ribbon.

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