JPH08332667A - Production of tubular member - Google Patents
Production of tubular memberInfo
- Publication number
- JPH08332667A JPH08332667A JP7141839A JP14183995A JPH08332667A JP H08332667 A JPH08332667 A JP H08332667A JP 7141839 A JP7141839 A JP 7141839A JP 14183995 A JP14183995 A JP 14183995A JP H08332667 A JPH08332667 A JP H08332667A
- Authority
- JP
- Japan
- Prior art keywords
- tubular body
- cooling
- hole
- cooling medium
- passage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、合成樹脂からなり、管
壁に管軸方向の通孔が複数本並設された管状体を製造す
る方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tubular body made of a synthetic resin, in which a plurality of through holes in the axial direction of the tube are juxtaposed in a tube wall.
【０００２】[0002]
【従来の技術】従来、合成樹脂管状体の製造方法として
は、押出機の先端に環状の樹脂通路を有する金型を付設
し、押出機により溶融・混練された樹脂を金型から管状
に押出して冷却成形工程に送り込むのが通例である。こ
の冷却成形工程での管状体は、金型の先端面、或いは水
槽等の冷却装置に取り付けられたサイジングダイを通過
し、寸法規制を受けながら冷却・賦形される。2. Description of the Related Art Conventionally, as a method for producing a synthetic resin tubular body, a die having an annular resin passage is attached to the tip of an extruder, and the resin melted and kneaded by the extruder is extruded into a tubular form from the die. It is customary to send it to the cooling molding process. In this cooling molding step, the tubular body passes through the tip surface of the mold or a sizing die attached to a cooling device such as a water tank, and is cooled and shaped while being subjected to dimensional restrictions.
【０００３】この冷却成形工程では、その外表面、或い
は内表面からの冷却により賦形されるので、内外の表面
層と内部層との間で冷却速度が相違し、また、収縮・固
化を開始する時点がずれるので、管状体内部に残留応力
が蓄積された状態となることが知られている。例えば、
デュポン・カナダ社の研究センターの刊行物「ＡＮＴＥ
Ｃ」の、１９８９年版：５４６〜５４９頁に掲載された
論文「プラスチックパイプ及び異形押出成形に於ける残
留応力分布の考察（ Prediction of ResidualStress Di
stribution in Plastic Pipe and Profile Extrusion )
」でも、このことが指摘されている。In this cooling molding step, since the shape is formed by cooling from the outer surface or the inner surface, the cooling rate is different between the inner and outer surface layers and the inner layer, and contraction / solidification is started. It is known that the residual stress is accumulated inside the tubular body because the time points for doing so shift. For example,
The publication "ANTE" of the research center of DuPont Canada
C ", 1989 edition: 546-549," A study of residual stress distribution in plastic pipe and profile extrusion molding (Prediction of ResidualStress Di
stribution in Plastic Pipe and Profile Extrusion)
", But this is pointed out.
【０００４】[0004]
【発明が解決しようとする課題】この残留応力のため、
成形された管状体の寸法が不均一になる場合があり、特
に管端が変形する傾向が強く、その為に管状体同士、管
状体と接手との接続がし難いという問題がある。また、
使用中に外圧或いは内圧等の外力が加わった場合、その
外力と残留応力との方向が一致した際に管が偏平になっ
たり、亀裂を起こしたりし易いという問題もある。Due to this residual stress,
The formed tubular body may have non-uniform dimensions, and the tube ends are particularly prone to deformation, which makes it difficult to connect the tubular bodies to each other and to connect the tubular body and the joint. Also,
When an external force such as an external pressure or an internal pressure is applied during use, there is also a problem that the pipe is likely to be flat or cracked when the direction of the external force and the direction of the residual stress match.
【０００５】この問題を解決する方法も幾つか開発され
ている。例えば、特公平４−２５１２９号公報には、金
型から押出された管状体を、冷却・固化工程に導入する
際に、急冷することなく先ず表面層だけを所定温度まで
冷却し、次いで空冷・液冷を複数回繰り返して、徐々に
内層まで完全に冷却するようにする技術が開示されてい
る。Several methods have been developed to solve this problem. For example, in Japanese Examined Patent Publication No. 25129/1992, when a tubular body extruded from a mold is introduced into a cooling / solidifying step, only the surface layer is first cooled to a predetermined temperature without being rapidly cooled, and then air-cooled. A technique is disclosed in which liquid cooling is repeated a plurality of times to gradually and completely cool the inner layer.
【０００６】しかしながら、この方法では、徐冷工程が
長く、管状体を完全に冷却・固化するまでの時間がかか
り過ぎて製造速度が低下するばかりでなく、前記表面層
と内部層との収縮・固化を開始する時点のずれを解消す
るには至らず、根本的な解決策とはなっていない。However, in this method, the slow cooling process is long, and it takes too much time to completely cool and solidify the tubular body, which not only slows down the production rate, but also shrinks and shrinks the surface layer and the inner layer. It is not a fundamental solution because the gap between the start of solidification cannot be resolved.
【０００７】本発明は、上記従来技術の欠点を解消し、
押出成形された樹脂管状体の残留応力が少なく、寸法的
にも物性的にも欠陥のないものが得られる製造方法を提
供することを目的とする。The present invention solves the above-mentioned drawbacks of the prior art,
An object of the present invention is to provide a production method by which a resin tubular body formed by extrusion has a small residual stress and is free from defects in terms of dimensions and physical properties.
【０００８】[0008]
【課題を解決するための手段】本発明の管状体の製造方
法は、「環状の樹脂通路の出口側に、内部の軸方向に流
体通路を有するピンを、複数本間隔を隔てて配設してな
る金型から管状体を押出すにあたり、型外より前記ピン
の流体通路に冷却媒体を導入し、この冷却媒体を前記ピ
ンにより管状体に管軸方向に形成された通孔内に送り込
むこと」を特徴とするものであり、このことにより上記
目的が達成される。According to the method for manufacturing a tubular body of the present invention, "a plurality of pins having fluid passages in the inner axial direction are arranged at the outlet side of an annular resin passage at intervals. When the tubular body is extruded from the die, the cooling medium is introduced from the outside of the die into the fluid passage of the pin, and the cooling medium is fed into the through hole formed in the tubular body by the pin in the axial direction of the tubular body. The above-mentioned object is achieved by this.
【０００９】本発明の製造方法に使用される樹脂として
は、主として、押出成形に汎用される樹脂ならば何でも
採用可能であって、例えば、ポリエチレン、ポリプロピ
レン、ポリブテンに代表されるオレフィン系樹脂、ポリ
テトラフルオロエチレン、ポリビニルジフルオロライド
等のフッ素系樹脂、ポリエチレンテレフタレート、ナイ
ロン、ポリフェニレンスルフィド、ポリエーテルエーテ
ルケトン等の結晶性エンジニアプラスチック等が挙げら
れる。As the resin used in the production method of the present invention, any resin generally used in extrusion molding can be mainly used, and examples thereof include olefin resins represented by polyethylene, polypropylene and polybutene, and poly resins. Fluorine-based resins such as tetrafluoroethylene and polyvinyl difluoride, and crystalline engineered plastics such as polyethylene terephthalate, nylon, polyphenylene sulfide, and polyether ether ketone.
【００１０】また、非晶性樹脂としては、ポリビニルク
ロライド、ポリ塩化ビニリデン、ポリカーボネート、ポ
リメチルメタクリレート、ポリビニルアルコール、ポリ
エーテルスルフィド、ポリエーテルイミド、ポリイミド
等が挙げられる。Examples of the amorphous resin include polyvinyl chloride, polyvinylidene chloride, polycarbonate, polymethyl methacrylate, polyvinyl alcohol, polyether sulfide, polyether imide and polyimide.
【００１１】また、上記主材料となる樹脂に対して、ガ
ラスチョップドストランド、炭酸カルシウム、バルーン
状高炉灰等の充填材、ハロゲン系、ノンハロゲン系、無
機系の各種難燃剤、ヒンダードアミン系、ベンゾフェノ
ン系等の紫外線吸収剤、着色剤、可塑剤等の各種添加剤
が、必要に応じて使用可能である。Further, in addition to the resin as the main material, fillers such as glass chopped strands, calcium carbonate, balloon-shaped blast furnace ash, halogen-based, non-halogen-based, inorganic-based flame retardants, hindered amine-based, benzophenone-based, etc. Various additives such as UV absorbers, colorants, and plasticizers can be used as necessary.
【００１２】本発明において使用される金型の基本的な
構造としては、管状体の押出成形に汎用されている金型
と同じ物が使用される。例えば、外型と芯型とがスパイ
ダーによって支持され、その間の環状空洞内を樹脂通路
としたもの等である。As the basic structure of the mold used in the present invention, the same structure as the mold generally used for extrusion molding of tubular bodies is used. For example, the outer die and the core die are supported by a spider, and an annular cavity between them is used as a resin passage.
【００１３】しかしながら、本発明ではこの樹脂通路の
出口側に、軸方向即ち長手方向の内部に流体通路を形成
したピンを複数本配設したものを使用することが重要な
要素の一つである。このピンを樹脂通路内で固定する手
段としては外型、芯型何れを利用してもよいが、型外か
ら冷却媒体を導入することを考慮して、芯型から導入す
る場合は芯型、外型から導入する場合は外型にそれぞれ
固定するのがよい。However, in the present invention, one of the important elements is to use a plurality of pins having a fluid passage formed in the axial or longitudinal direction on the outlet side of the resin passage. . As a means for fixing this pin in the resin passage, either an outer mold or a core mold may be used, but in consideration of introducing the cooling medium from outside the mold, when introducing from the core mold, a core mold, When introducing from the outer mold, it is preferable to fix each to the outer mold.
【００１４】本発明では、このピンの存在により、押し
出された管状体には、管軸方向にピンと同じ本数の通孔
が必然的に形成される。この通孔の数及び大きさについ
ては、次の〜の各項に記載の制約の全てを満足する
ように配慮するのが好ましい。また、通孔の形状はピン
の横断面形状に応じて定まり、特に限定されないが、成
形性、強度保持性等の点から、丸孔状とするのが好まし
い。In the present invention, due to the presence of this pin, the extruded tubular body is necessarily formed with as many through holes as the number of pins in the axial direction of the tube. Regarding the number and size of the through holes, it is preferable to consider so as to satisfy all the restrictions described in the following items (1) to (4). The shape of the through hole is determined according to the cross-sectional shape of the pin and is not particularly limited, but it is preferably a round hole from the viewpoint of moldability, strength retention and the like.
【００１５】．管壁の厚み方向の通孔内法を、管壁の
周方向の通孔内法で除した値は、１／４〜４であるこ
と。小さくなると、管壁の周方向に占める通孔内法が大
きくなり、大きくなると、通孔壁面と管状体表面との間
隔が小さくなりすぎて、何れの場合でも管状体全体の強
度が低下する。 ．管壁の周方向の通孔内法と通孔数との積を、通孔同
士の間隔の合計値で除した値は、２以下であること。大
きくなると、通孔同士の周方向の間隔が管壁の周方向の
通孔内法に比べて小さくなり、管状体全体の強度が低下
する。 ．通孔の数は３以上であること。通孔の数は少なくな
ると、管壁の冷却効果が不足し、残留応力低下の効果が
得られない。[0015] The value obtained by dividing the through-hole method in the pipe wall thickness direction by the through-hole method in the pipe wall circumferential direction is 1/4 to 4. When it becomes smaller, the inner diameter of the through hole occupying the circumferential direction of the tube wall becomes larger, and when it becomes larger, the distance between the wall surface of the through hole and the surface of the tubular body becomes too small, and in any case, the strength of the entire tubular body decreases. ． The value obtained by dividing the product of the inner diameter of the through hole in the circumferential direction of the pipe wall and the number of through holes by the total value of the intervals between the through holes should be 2 or less. When it becomes larger, the distance between the through holes in the circumferential direction becomes smaller than that in the method of the through hole in the circumferential direction of the tube wall, and the strength of the tubular body as a whole decreases. ． The number of through holes must be 3 or more. When the number of through holes is small, the effect of cooling the pipe wall is insufficient and the effect of reducing residual stress cannot be obtained.
【００１６】．管壁の厚み方向の通孔内法を、管壁の
厚みで除した値は、１／１０〜１／２であること。小さ
くなると、通孔の大きさが小さくなり残留応力低下の効
果が得られず、大きくなると、通孔壁面と管状体表面と
の間隔が小さくなりすぎて管状体全体の強度が低下す
る。 ．通孔壁面とこれに近い方の管状体表面との間隔を、
管壁の厚みで除した値は、１／８以上であること。小さ
くなると、通孔壁面と管状体表面との間隔が小さく な
りすぎて管状体全体の強度が低下する。.. The value obtained by dividing the through-hole method in the thickness direction of the pipe wall by the thickness of the pipe wall is 1/10 to 1/2. When it becomes smaller, the size of the through hole becomes smaller and the effect of reducing the residual stress cannot be obtained. When it becomes larger, the distance between the wall surface of the through hole and the surface of the tubular body becomes too small, and the strength of the entire tubular body lowers. ． The distance between the wall surface of the through hole and the surface of the tubular body closer to this,
The value divided by the thickness of the tube wall should be 1/8 or more. When it becomes smaller, the distance between the wall surface of the through hole and the surface of the tubular body becomes too small, and the strength of the entire tubular body decreases.
【００１７】本発明では、ピン内に設けられた流体通路
を経由して、この各通孔内に冷却媒体を送り込むという
手段を採ることも重要な要素の一つである。このときの
冷却媒体源としては、冷却空気、冷却水、液体窒素、液
体炭酸、或いはアルコール、アセトン等の有機溶媒等が
使用される。In the present invention, it is also an important factor to adopt a means of feeding the cooling medium into each of the through holes via the fluid passage provided in the pin. As the cooling medium source at this time, cooling air, cooling water, liquid nitrogen, liquid carbonic acid, or an organic solvent such as alcohol or acetone is used.
【００１８】また、金型におけるこの冷却媒体導入路の
周壁や、樹脂通路内におけるピンの外表面、流体通路の
内表面等には、断熱材層を設けるのがよい。冷却媒体を
送り込むときの形態は、吹き込み、流し込み、噴霧状で
の吹き付け等、冷却媒体に応じた適宜の形態でよい。通
孔内に送り込まれた冷却媒体は、管状体成形の最終段階
で定尺に切断される際に除去される。Further, it is preferable to provide a heat insulating material layer on the peripheral wall of the cooling medium introducing passage in the mold, the outer surface of the pin in the resin passage, the inner surface of the fluid passage, and the like. The form in which the cooling medium is fed may be an appropriate form depending on the cooling medium, such as blowing, pouring or spraying. The cooling medium sent into the through hole is removed when the tube is cut into a regular size in the final stage of forming the tubular body.
【００１９】本発明に於ける、かかる管状体の通孔内か
らの冷却方法を採用した場合、従来から実施されている
管状体の外表面や内表面からの冷却、例えば冷却された
円筒状のサイジングダイの内面に管状体の外表面を摺動
させる方法、或いは、ダイ先端から突出し、内部には冷
却媒体が循環しているマンドレルの外面に管状体の内表
面を摺動させる方法等を必要に応じて実施してもよい。When the cooling method from the inside of the through hole of the tubular body is adopted in the present invention, cooling from the outer surface or the inner surface of the tubular body which has been conventionally carried out, for example, a cooled cylindrical shape is performed. Need a method of sliding the outer surface of the tubular body on the inner surface of the sizing die, or a method of sliding the inner surface of the tubular body on the outer surface of the mandrel that projects from the die tip and circulates the cooling medium inside. It may be carried out according to
【００２０】以下、本発明について図面を参照しながら
詳細に説明する。The present invention will be described in detail below with reference to the drawings.
【００２１】図１は本発明の管状体の製造方法の実施に
用いて好適な装置の一例を示す要部のみの断面図であ
り、図２は同上装置を用いて成形された管状体の、それ
ぞれ異なる例を示す横断面図である。FIG. 1 is a sectional view showing only an essential part of an example of an apparatus suitable for carrying out the method for producing a tubular body of the present invention, and FIG. 2 shows a tubular body formed by using the same apparatus. It is a cross-sectional view showing a different example.
【００２２】図１において、１は押出機のシリンダーで
あり、内部に単軸スクリュー２が配設されている。３は
シリンダー１の前端に付設された金型であって、外型４
と芯型５とを有し、外型４の出口側には細径のランド部
６が設けられている。芯型５は、その根元に固定された
スパイダー７により外型４内に支持されており、かくし
て環状の樹脂通路８が形成され、ここまでの構造は、従
来の金型と同じである。In FIG. 1, reference numeral 1 is a cylinder of an extruder in which a single screw 2 is arranged. 3 is a die attached to the front end of the cylinder 1, and is an outer die 4
And a core die 5, and a land portion 6 having a small diameter is provided on the outlet side of the outer die 4. The core die 5 is supported in the outer die 4 by a spider 7 fixed to the root thereof, thus forming an annular resin passage 8, and the structure up to this point is the same as the conventional die.
【００２３】この環状の樹脂通路８の出口側内に、ピン
９が複数本、等間隔に配設されており、外型４の内壁か
ら樹脂通路８内に突設した支持部１０により、該外型４
に固定されている。各ピン９内には、その内部の軸方向
に流体通路１１が設けられ、先端開口部１２は、ランド
部６や芯型５の端面と面一になされている。また、後部
はそれぞれ外側に屈折され、支持部１０内の貫通孔を経
由して外型４に貫設された冷却媒体導入路１３に連通さ
れ、型外に設置された図示しない冷却媒体源に連結され
ている。１４は流体通路１１、支持部１０内の貫通孔及
び冷却媒体導入路１３の内壁に張着された断熱材層、１
５は管状体Ｐの管壁に形成された通孔である。Inside the outlet side of the annular resin passage 8, a plurality of pins 9 are arranged at equal intervals, and a support portion 10 protruding from the inner wall of the outer die 4 into the resin passage 8 serves to External type 4
It is fixed to. A fluid passage 11 is provided in each pin 9 in the axial direction thereof, and the tip end opening 12 is flush with the end surface of the land portion 6 and the core die 5. Further, the rear parts are respectively bent to the outside, communicated with the cooling medium introducing passage 13 penetrating the outer mold 4 through the through holes in the supporting part 10, and to a cooling medium source (not shown) installed outside the mold. It is connected. Reference numeral 14 is a fluid passage 11, a through hole in the support portion 10 and a heat insulating material layer stretched on the inner wall of the cooling medium introduction passage 13.
Reference numeral 5 is a through hole formed in the tube wall of the tubular body P.
【００２４】[0024]
【作用】本発明の管状体の製造方法は、環状の樹脂通路
の出口側に、内部の軸方向に冷却媒体の通過可能な流体
通路を有するピンを複数本、間隔を隔てて配設してなる
金型から、管状体を押し出す方法を採ったので、管軸方
向に通孔が形成された管状体が連続的に押し出され、且
つこの通孔はピンの流体通路に連通したものとなる。According to the method for manufacturing a tubular body of the present invention, a plurality of pins having fluid passages through which the cooling medium can pass in the inner axial direction are arranged at the outlet side of the annular resin passages at intervals. Since the tubular body is extruded from the die, the tubular body having a through hole formed in the tube axial direction is continuously extruded, and the through hole communicates with the fluid passage of the pin.
【００２５】また、上記押出成形工程中に、型外より冷
却媒体を、ピンの流体通路を経由して通孔内に送り込む
ようにしたから、金型から押出された管状体の、冷却・
固化工程では、通孔からも冷却され、管状体全体にわた
って、殆ど同時に冷却・固化が開始される。従って、管
状体全体の冷却速度が速くなると共に、管状体の表面層
と内部層との間の冷却・固化のタイミングのずれや、冷
却速度の差が殆ど無くなり、管状体内の残留応力の発生
を極力抑えることができる。Further, during the above-mentioned extrusion molding process, the cooling medium is fed from the outside of the mold into the through hole through the fluid passage of the pin, so that the tubular body extruded from the mold is cooled and cooled.
In the solidification step, cooling is also performed from the through holes, and cooling / solidification is started almost simultaneously over the entire tubular body. Therefore, the cooling rate of the entire tubular body is increased, the timing difference of the cooling and solidification between the surface layer and the inner layer of the tubular body and the difference in the cooling rate are almost eliminated, and the residual stress in the tubular body is not generated. It can be suppressed as much as possible.
【００２６】[0026]
〔実施例１、２〕上述の装置を用い、次の通りの成形材
料、成形条件により管状体を押出成形した。尚、管壁内
からの冷却の他に、冷却サイジング方式として、通常の
バキューム噴霧式外径規制方式を採用した。尚、押出機
１のスクリュー径＝７５φ、ピンの本数＝１６、ピンの
断面形状＝円形のものを用いた。 成形材料：ポリエチレン（三井石油化学社製、２０１５
Ｍ） 成形条件：温度条件は、シリンダー＝２２０℃、金型＝
２００℃冷却媒体として、冷却空気（温度＝２０℃、流
量＝１００リットル／時）と、噴霧状冷却水（温度＝１
５℃、流量＝１００リットル／時）の２種類を用い、そ
れぞれ実施例１、２とした。 得られた管状体の外径＝１６５ｍｍ、内径＝１３９ｍ
ｍ、通孔径＝６．５ｍｍ、通孔数１６、通孔の位置＝そ
れぞれ等間隔で且つ管状体の肉厚方向の中央であった。
その断面形状を図２（イ）に示す。[Examples 1 and 2] Using the above apparatus, a tubular body was extruded by the following molding materials and molding conditions. In addition to cooling from the inside of the pipe wall, a normal vacuum spray type outer diameter regulation system was adopted as a cooling sizing system. In addition, the screw diameter of the extruder 1 was 75φ, the number of pins was 16, and the cross-sectional shape of the pins was circular. Molding material: polyethylene (Mitsui Petrochemical Co., Ltd., 2015
M) Molding conditions: temperature conditions: cylinder = 220 ° C., mold =
Cooling air (temperature = 20 ° C., flow rate = 100 liters / hour) and atomized cooling water (temperature = 1
Examples 1 and 2 were used by using two types (5 ° C., flow rate = 100 liter / hour). The obtained tubular body has an outer diameter of 165 mm and an inner diameter of 139 m.
m, through-hole diameter = 6.5 mm, number of through-holes 16, positions of through-holes = equal spacing and center in the thickness direction of the tubular body.
The cross-sectional shape is shown in FIG.
【００２７】〔比較例１〕通孔内に冷却媒体を送り込ま
ず、通孔内は外気と連通した状態としたこと以外は実施
例１と同様にして管状体を製造した。Comparative Example 1 A tubular body was manufactured in the same manner as in Example 1 except that the cooling medium was not fed into the through hole and the inside of the through hole was in communication with the outside air.
【００２８】〔比較例２〕金型にピンを装着したものを
使用しなかったこと以外は実施例１と同様にして管状体
を製造した。[Comparative Example 2] A tubular body was produced in the same manner as in Example 1 except that a mold equipped with pins was not used.
【００２９】上記各実施例及び比較例で得られた管状体
について、蓄積された残留応力を測定した。尚、測定方
法は輪切りにした管状体片に、管軸を通る平面で切れ目
を一箇所入れて切断、外径の変化量を測定し、その数値
を次式に代入して算出した。The accumulated residual stress was measured for the tubular bodies obtained in the above Examples and Comparative Examples. In addition, the measuring method was calculated by inserting a cut in a plane passing through the tube axis into a sliced tubular body piece, cutting and measuring the amount of change in outer diameter, and substituting the numerical value into the following equation.
【００３０】σmax ＝〔±Ｅ（ｔ）ｈ〕／〔１−
ν2 〕×〔Ｄ2 （ｔ）−Ｄ1 〕／〔Ｄ2 （ｔ）Ｄ1 〕 （注）σmax ：管状体の最大応力（Ｋｇｆ／ｃｍ2) Ｅ（ｔ）：タイムｔのときのクリープ係数 ｈ ：管状体の肉厚 Ｄ1 ：切断前の直径 Ｄ2(ｔ）：タイムｔに於ける切断後の直径 ν ：ポアソン比Σ max = [± E (t) h] / [1-
ν 2 ] × [D 2 (t) -D 1 ] / [D 2 (t) D 1 ] (Note) σ max : maximum stress of the tubular body (Kgf / cm 2 ) E (t): at time t Coefficient h of h: tubular wall thickness D 1 : diameter before cutting D 2 (t): diameter after cutting at time t ν: Poisson's ratio
【００３１】その結果、実施例１及び２の場合は、それ
ぞれ順に３０及び２５(Kgf/cm2) であったのに対し、比
較例１及び２の場合は、それぞれ順に５０及び６０(Kgf
/cm2) であり、残留応力低下の効果が著しいことが明ら
かである。As a result, in the cases of Examples 1 and 2, the values were 30 and 25 (Kgf / cm 2 ) respectively, whereas in the cases of Comparative Examples 1 and 2, 50 and 60 (Kgf) respectively.
/ cm 2 ) and it is clear that the effect of reducing residual stress is remarkable.
【００３２】上記実施例では、通孔の形状が円形のもの
の例を示したが、ピンの形状次第では、前述の通り各種
の形状のものが得られる。その一例を図２（ロ）に示
す。同図において１６は方形状の通孔である。In the above embodiment, the through holes have a circular shape, but various shapes can be obtained as described above depending on the shape of the pin. An example thereof is shown in FIG. In the figure, 16 is a rectangular through hole.
【００３３】[0033]
【発明の効果】本発明の管状体の製造方法は、管状体の
押出成形において、その冷却・固化の段階で、管状体に
形成される通孔から冷却するという方法を採ったので、
冷却速度が速くなり、製造速度の向上を図ることができ
る。また、管状体の肉厚方向における、各部での冷却速
度の相違や、冷却・固化開始のタイミングのずれが少な
くなり、管状体内の残留応力の発生を極力抑えることが
できる。従って、寸法安定性に優れたものを製造するこ
とができる。As described above, the tubular body manufacturing method of the present invention employs a method of cooling from the through-holes formed in the tubular body in the step of cooling and solidifying the tubular body in the extrusion molding.
The cooling rate becomes faster, and the production rate can be improved. Further, the difference in the cooling rate at each portion in the thickness direction of the tubular body and the deviation of the timing of the start of cooling / solidification are reduced, and the occurrence of residual stress in the tubular body can be suppressed as much as possible. Therefore, a product having excellent dimensional stability can be manufactured.
【００３４】また、本発明の製造方法によって得られる
管状体は、管軸方向に通孔が形成されたものであるの
で、管状体の軽量化がなされる。Further, since the tubular body obtained by the manufacturing method of the present invention has the through hole formed in the axial direction of the pipe, the weight of the tubular body can be reduced.
【図１】本発明の管状体の製造方法の実施に用いて好適
な装置の一例を示す要部のみの断面図である。FIG. 1 is a cross-sectional view of only a main part showing an example of an apparatus suitable for carrying out the method for manufacturing a tubular body of the present invention.
【図２】同上装置によって製造された管状体の、それぞ
れ異なる例を示す断面図である。FIG. 2 is a cross-sectional view showing different examples of tubular bodies manufactured by the same apparatus.
Ｐ 管状体 ３ 金型 ４ 外型 ５ 芯型 ６ ランド部 ７ スパイダー ８ 環状の樹脂通路 ９ ピン 11 流体通路 13 冷却媒体導入路 15、16 通孔 P Tubular body 3 Mold 4 Outer type 5 Core type 6 Land portion 7 Spider 8 Annular resin passage 9 Pin 11 Fluid passage 13 Cooling medium introduction passage 15, 16 Through hole
Claims (1)
向に流体通路を有するピンを、複数本間隔を隔てて配設
してなる金型から管状体を押出すにあたり、型外より前
記ピンの流体通路に冷却媒体を導入し、この冷却媒体を
前記ピンにより管状体に管軸方向に形成された通孔内に
送り込むことを特徴とする管状体の製造方法。1. When extruding a tubular body from a die having a plurality of pins having fluid passages in the inner axial direction at the outlet side of an annular resin passage with a space provided therebetween, the tubular body is pressed from outside the die. A method for manufacturing a tubular body, comprising introducing a cooling medium into a fluid passage of the pin, and feeding the cooling medium into a through hole formed in the tubular body in the tube axial direction by the pin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7141839A JPH08332667A (en) | 1995-06-08 | 1995-06-08 | Production of tubular member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7141839A JPH08332667A (en) | 1995-06-08 | 1995-06-08 | Production of tubular member |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08332667A true JPH08332667A (en) | 1996-12-17 |
Family
ID=15301357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7141839A Pending JPH08332667A (en) | 1995-06-08 | 1995-06-08 | Production of tubular member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08332667A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007003717A1 (en) * | 2005-07-04 | 2007-01-11 | Maillefer S.A. | Extrusion method and extrusion apparatus |
| WO2007068792A1 (en) * | 2005-12-14 | 2007-06-21 | Conenor Oy | Method for making a composite product, and a composite product |
| WO2011129259A1 (en) * | 2010-04-13 | 2011-10-20 | 株式会社Ihi | Induction heating roll device |
-
1995
- 1995-06-08 JP JP7141839A patent/JPH08332667A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007003717A1 (en) * | 2005-07-04 | 2007-01-11 | Maillefer S.A. | Extrusion method and extrusion apparatus |
| WO2007068792A1 (en) * | 2005-12-14 | 2007-06-21 | Conenor Oy | Method for making a composite product, and a composite product |
| WO2011129259A1 (en) * | 2010-04-13 | 2011-10-20 | 株式会社Ihi | Induction heating roll device |
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