JP4021976B2 - Manufacturing method of multilayer pipe - Google Patents

Manufacturing method of multilayer pipe Download PDF

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Publication number
JP4021976B2
JP4021976B2 JP25152497A JP25152497A JP4021976B2 JP 4021976 B2 JP4021976 B2 JP 4021976B2 JP 25152497 A JP25152497 A JP 25152497A JP 25152497 A JP25152497 A JP 25152497A JP 4021976 B2 JP4021976 B2 JP 4021976B2
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Prior art keywords
tube
pipe
diameter
taper
raw
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JPH1182824A (en
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建平 莫
豊 関戸
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Sango Co Ltd
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Sango Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

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  • Rigid Pipes And Flexible Pipes (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は１本の管を反転状に折曲して多層管を製造する多層管の製造方法に関する。
【０００２】
【従来の技術】
従来、１本の管を反転状に折曲して多層管を製造する方法として、素管の一部を拡管した後、素管側端と拡管側端を管軸方向に加圧して、図１０に示すように拡管部１００を連続的に座屈して拡管部１００内に素管部１０１を挿入するようにしたものが例えば特公昭４７−１４５３５号公報に開示されている。これを第１の従来の技術とする。
【０００３】
また、図１１に示すように、素管の一部を縮管して素管部２００とテーパ部２０１と小径管部２０２を連続して形成し、その後に管を軸方向に加圧してテーパ部２０１を座屈させて素管内に縮管部を挿入するようにしたものが例えば特開昭５７−９０４８８号公報に開示されている。これを第２の従来の技術とする。
【０００４】
【発明が解決しようとする課題】
上記第１の従来の技術においては、拡管部１００が、拡管時に引っ張りの塑性加工を受けた上に折曲反転による引っ張り加工を再度受けることとなり、また、該部１００の板厚も減少しているため脆弱化し、折曲反転加工時に図１０に示す反転部分２０３に割れを生じやすい問題がある。
【０００５】
また、上記第２の従来の技術においては、縮管部であるテーパ部２０１で反転されるため上記のような割れのおそれがないが、その素管部２００とテーパ部２０１の境界部２０３のアールと、縮管部２０２とテーパ部２０１の境界部２０４のアールとが同一であることから、管の押圧時において、図１２に示すように、テーパ部２０１の小径側の肉がテーパ部２０１の大径側の肉より先に流れてテーパ部２０１の小径側から順に座屈し、テーパ部２０１が外側へ膨出する現象が生じたり、また図１３に示すように縮管部２０２である小径管部に曲がりや傾きが生じ、理想的な折曲反転形状が得難いという問題がある。
【０００６】
そこで本発明は、上記の問題を解決する多層管の製造方法を提供することを目的とするものである。
【０００７】
【課題を解決するための手段】
上記の課題を解決するために、請求項１記載の第１の発明は、素管の一部に縮管加工を施して素管部とテーパ部と小径管部を連続状態に形成する縮管工程と、素管部とテーパ部の境界部のアールを小径管部とテーパ部の境界部のアールよりも大きくするアール付け工程と、素管部と小径管部が相互に近づく方向へ押圧してテーパ部を順次座屈させる座屈工程とからなることを特徴とするものである。
【０００８】
本発明においては、素管部とテーパ部の境界部のアールを小径管部とテーパ部の境界部のアールよりも大きくしたので、座屈工程において、テーパ部の大径側から順に内側へ座屈し、テーパ部の大径側が外側へ膨出することない。そのため、素管部も内側へ順次座屈し、内側への座屈が連続的にスムーズに行われる。
【０００９】
更に、縮管加工は引っ張りの塑性加工ではないので、テーパ部は、該部の座屈時のみ引っ張り加工されることになり、座屈加工時の引っ張りによってテーパ部の割れは発生しない。更に、縮管加工は板厚減少を招かないので、その材料の強度低下が防止され、これも割れ防止に貢献する。
【００１０】
請求項２記載の第２の発明は、上記第１の発明において、アール付け工程前に、素管部を拡張して大径部に形成する工程を有するものである。
本発明においては、上記第１の発明と同様の作用を発揮する上に、小径管部と大径管部との直径差が大きくなり、座屈加工時における所期の連続座屈変形が発生しやすくなる。
【００１１】
請求項３記載の第３の発明は、上記第１又は第２の発明において、アール付け工程において、先端肩部にアール部を有するパンチを素管部又は大径管部とテーパ部との境界部の内面に押圧して、その境界部をパンチのアール部でアール付け加工を施すようにしたものである。
【００１２】
本発明においては、アール付け加工が、アール部を有するパンチを使用して容易に行うことができる。
【００１３】
【発明の実施の形態】
図１乃至図９に示す実施例に基づいて本発明の実施の形態について説明する。
図１乃至図４は第１実施例の製造方法を示す。
【００１４】
先ず金属製のパイプ（素管）の一部（一方側）に縮管加工を施して該部を小径管部３とし、図１に示すように、素管部１とテーパ部２と小径管部３が連続した管を形成する。この縮管加工によっては小径管部３の板厚は、素管より減少しない。
【００１５】
この縮管加工方法としては、例えば図２（ａ）に示すように、素管部１の内径と同一径の大径凸形４ａを有する型４と、小径管部３の外径と同径の小径凹型５ａとテーパ凹型５ｂを有する型５とを設け、図２（ｂ）に示すように、素管部１の一方端から大径凸型４ａを押圧挿入し、他方端からテーパ凹型５ｂと小径凹型５ａを押圧挿入して縮管加工を施す。また、この縮管加工は、その他スウェージングなどの周知の方法で行ってもよい。
【００１６】
なお、実際の製造に際しては、素管１として、材質がＳＵＳ４０９、管直径Ｄ1 がφ２５．４ｍｍ、板厚ｔが１ｍｍのものを使用した。また、縮管加工においては、上記の素管（２５．４ｍｍ）を直径ｄがφ１７ｍｍになるまで縮管して小径管部３を形成した。
【００１７】
次に、図３に示すように、先端肩部６ａにアールＲ3 を形成したパンチ６を用い、小径管部３の開口端側を部材７で固定して、パンチ６を素管部１の開口端側より挿入し、素管部１とテーパ部２の境界部１ａに先端肩部６ａのアールＲ3 によって押圧荷重Ｐ1 を加え、その境界部１ａにアールＲ1 を形成する。該アールＲ1 の半径は、小径管部３とテーパ部２との境界部３ａのアールＲ2 よりも大きく設定する。
【００１８】
次に、図４に示すように、素管部１の開口端側を部材７ａで固定し、小径管部３に圧縮荷重Ｐ2 を加えて小径管部３を素管部１方向へ押圧する。このとき、素管部１とテーパ部２との境界部１ａのアールＲ1 が小径管部３とテーパ部２との境界部３ａのアールＲ2 よりも大きいため、荷重Ｐ2 によってテーパ部２の小径側よりも大径側（素管側）が先に内側へ座屈し、テーパ部２が外側へ膨出することを防止する。そのため、上記の圧縮荷重Ｐ2 を連続的に加えることにより、テーパ部２の素管部１側から順次内側へスムーズに連続して座屈変形し、小径管部３の曲りや傾きが発生することなく、図４に示すような三層管が成形される。
【００１９】
また、前工程である上記の縮管加工は引っ張り加工ではないので、管の引っ張り加工は上記座屈加工時のみとなり、テーパ部の脆弱化が少なく、座屈加工時の引っ張りにより管の割れは発生しない。また、縮管加工は板厚減少を招かないので、テーパ部２における材料の強度低下を防ぐことができ、これも管の割れ防止に貢献する。
【００２０】
なお、上記の縮管加工時において、その縮管工程を複数工程で行い、縮径を大きくしてもよい。例えば上記のφ２５．４の素管を第１縮管工程でｄ＝φ１７としたり、また、第２縮管工程でｄ＝φ１４までに縮管してもよい。
【００２１】
図５乃至図７は第２実施例の製造方法を示す。
本実施例は、先ず金属製のパイプ（素管）一部（一方側）を上記第１実施例と同様に縮管加工を施して該部を小径にし、他方側を拡管加工して大径にし、図５に示すように大径部１ｂとテーパ部２と小径管部３が連続した管を形成する。この拡管加工方法としては、例えば上記図２（ａ）に示す大径凸型４ａを素管内径より大径のものにしたり、その他周知の拡管加工方法で行う。
【００２２】
また、この実施例として実際に使用した素管１は上記第１実施例での素管１と同じものを使用した。また、小径管部３は上記第１実施例と同様ｄ＝φ１７ｍｍ又はφ１４ｍｍまで縮管し、大径管部１ｂは、その直径Ｄ2 をφ２９．２ｍｍまで拡管した。
【００２３】
次に、図６（ａ）に示すように、先端肩部８ａにアールＲ4 を形成したパンチ８を使用して、上記第１実施例と同様のアール付け加工によって大径管部１ｂとテーパ部２との境界部１ａにアールＲ5 を形成する。該アールＲ5 の半径は小径管部３とテーパ部２との境界部３ａのアールＲ6 よりも大きく設定する。
なお、このとき、図６（ｂ）に示すように、テーパ部２も同時に拡げて、テーパ部２が管軸に対して略直角までに形成すると、後工程に効果的である。
【００２４】
次に、図７に示すように、大径管部１ｂの開口端部を部材７ａで固定し、小径管部３に圧縮荷重Ｐ4 を加えて小径管部３を大径管部１ｂ方向へ押圧する。このとき、Ｒ6 ＜Ｒ5 に形成されているため、上記第１実施例と同様にテーパ部２が外側へ膨出することなく座屈し、小径管部３の曲りや傾きが発生することなく図７に示すような三層管が形成される。
【００２５】
本第２実施例によれば、大径管部１ｂと小径管部３との直径差を大きくすることができ、座屈加工時における連続座屈変形が発生しやすくなる。また、大径管部１ｂの外形Ｄ2 が上記第１実施例の素管部１の外径Ｄ1 より大径の三層管が得られる。
【００２６】
なお、本第２実施例における大径管部１ｂの拡管率は１５％以下に設定し、拡管時に大きな引っ張りが発生しないようにする。
また、上記Ｒ1 とＲ2 との関係及びＲ5 とＲ6 との関係を、Ｒ2 ＜Ｒ1 、Ｒ6 ＜Ｒ5 にすると、大径側の肉が座屈に流れて座屈がより連続的にスムーズに進む。
【００２７】
また、上記第１実施例の素管部１又は第２実施例の大径管部１ｂの開口側端に図８に示すようなフランジ部１０を折曲形成することにより、フランジ部を有する三層管が得られる。
【００２８】
更に、上記第１実施例の素管部１又は第２実施例の大径管部１ｂの開口側部を折り返して外管部１１を形成することにより、Ｗ形状の四層管を形成することができる。この外側管１１の直径としては、例えば、上記素管部１を折曲する場合はφ３０ｍｍとし、大径管部１ｂを折曲する場合はφ３４．５ｍｍとする。また、外側管１１の開口端側にフランジ部１０を折曲形成してもよい。
【００２９】
なお、上記各実施例における各層の管の長さは所望に設定するもので、またその長さはテーパ部２の長さ、座屈長、折曲長などを所望に設定することにより所望に調節できる。
【００３０】
また、本発明により製造される多層管は、例えば内燃機関における樹脂インテークマニホールドのＥＧＲポートを形成する管などに使用されるもので、図８、図９に示すフランジ部１０によりインテークマニホールドなどに接続される。
【００３１】
【発明の効果】
以上のようであるから、請求項１記載の発明によれば、座屈加工時において、テーパ部及び素管部の内側への座屈がスムーズに連続して行われ、小径管部の曲りや傾きが防止され、理想的な折曲反転形状の多層管が製造できる。更に、管の割れの発生もない。
【００３２】
請求項２記載の発明によれば、更に、連続座屈変形が発生しやすく、多層管の製造が容易になる。
そして、請求項３記載の発明によれば、更に境界部のアール付け加工が簡易な構造で容易に行える。
【図面の簡単な説明】
【図１】本発明の第１実施例の製造方法における縮管工程を示す管の断面図。
【図２】（ａ）は図１の縮管工程に使用するダイスを示す断面図、（ｂ）はその加工状態を示す図。
【図３】図１の工程後のアール付け加工を示す管の断面図。
【図４】図３の工程後の座屈工程を示す管の断面図。
【図５】本発明の第２実施例の製造方法における縮管と拡管工程を示す管の断面図。
【図６】（ａ）は図５の工程後のアール付け加工を示す管の断面図、（ｂ）はこのアール付け加工と同時にテーパ部も管軸に対して略直角に折曲形成する例を示す要部拡大断面図。
【図７】図６の工程後の座屈工程を示す管の断面図。
【図８】図４又は図７の多層管にフランジ部を形成した多層管の断面図。
【図９】図４又は図７の多層管の外側管端をフランジ成形して、さらに外側管を折曲形成した多層管の断面図。
【図１０】従来の製造方法の第１例を示す管の断面図。
【図１１】従来の製造方法の第２例を示すもので拡管した管の断面図。
【図１２】図１１の管の加圧によるテーパ部の座屈状態を示す要部拡大断面図。
【図１３】図１１の管の加圧による管の曲がりを示す断面図。
【符号の説明】
１…素管部 １ａ，３ａ…境界部
１ｂ…大径管部 ２…テーパ部
３…小径管部 ６，８…パンチ
６ａ，８ａ…先端肩部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer tube, in which a single tube is bent in an inverted shape to manufacture a multilayer tube.
[0002]
[Prior art]
Conventionally, as a method of manufacturing a multilayer pipe by bending a single pipe in an inverted shape, after expanding a part of the raw pipe, press the raw pipe side end and the wide pipe side end in the pipe axis direction. As shown in FIG. 10, for example, Japanese Patent Publication No. 47-14535 discloses a structure in which the tube expansion portion 100 is continuously buckled and the raw tube portion 101 is inserted into the tube expansion portion 100. This is the first conventional technique.
[0003]
Further, as shown in FIG. 11, a part of the raw pipe is contracted to continuously form the raw pipe part 200, the taper part 201, and the small diameter pipe part 202, and then the pipe is pressurized in the axial direction to be tapered. For example, Japanese Patent Application Laid-Open No. 57-90488 discloses a method in which the portion 201 is buckled and the contracted tube portion is inserted into the raw tube. This is the second conventional technique.
[0004]
[Problems to be solved by the invention]
In the first prior art, the expanded portion 100 is subjected to tensile processing by bending reversal after undergoing tensile plastic processing during expansion, and the thickness of the portion 100 is also reduced. Therefore, there is a problem that it is weakened and easily breaks in the reversal portion 203 shown in FIG.
[0005]
Further, in the second conventional technique, since it is reversed by the tapered portion 201 which is a contraction tube portion, there is no fear of the above-described cracking, but the boundary portion 203 between the raw tube portion 200 and the tapered portion 201 is not affected. Since the radius and the radius of the boundary portion 204 of the contracted tube portion 202 and the taper portion 201 are the same, when the tube is pressed, as shown in FIG. Of the large diameter side of the taper portion 201 and buckled in order from the small diameter side of the taper portion 201, the taper portion 201 bulges outward, or the small diameter portion of the narrow tube portion 202 as shown in FIG. There is a problem in that the pipe portion is bent or inclined, and it is difficult to obtain an ideal folded inverted shape.
[0006]
Accordingly, an object of the present invention is to provide a method for manufacturing a multilayer pipe that solves the above-described problems.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a first invention according to claim 1 is a contracted tube in which a tube is subjected to a tube contracting process on a part of a tube to form a tube, a taper, and a small diameter tube in a continuous state. The process, the rounding process for making the radius of the boundary portion between the raw tube portion and the taper portion larger than the radius of the boundary portion between the small diameter tube portion and the taper portion, And a buckling step of sequentially buckling the taper portion.
[0008]
In the present invention, the radius of the boundary portion between the raw tube portion and the taper portion is made larger than the radius of the boundary portion between the small diameter tube portion and the taper portion. The large diameter side of the tapered portion does not bulge outward. For this reason, the raw tube portion is also sequentially buckled inward, and the inward buckling is continuously and smoothly performed.
[0009]
Further, since the tube shrinking process is not a plastic process of tension, the taper part is pulled only when the part is buckled, and the taper part is not cracked by the tension during the buckling process. Furthermore, since the tube contraction does not cause a reduction in the plate thickness, the strength of the material is prevented from being reduced, which also contributes to prevention of cracking.
[0010]
According to a second aspect of the present invention, in the first aspect, before the rounding step, the raw pipe portion is expanded to form a large diameter portion.
In the present invention, the same effect as in the first aspect of the present invention is exhibited, and the diameter difference between the small diameter pipe portion and the large diameter pipe portion is increased, and the expected continuous buckling deformation occurs during buckling. It becomes easy to do.
[0011]
According to a third aspect of the present invention, in the first or second aspect of the present invention, in the rounding step, the punch having the rounded portion at the tip shoulder portion is a boundary between the raw pipe portion or the large diameter pipe portion and the tapered portion. It presses against the inner surface of the part, and the boundary part is subjected to a rounding process at the rounded part of the punch.
[0012]
In the present invention, the rounding process can be easily performed using a punch having a rounded portion.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described based on the examples shown in FIGS.
1 to 4 show the manufacturing method of the first embodiment.
[0014]
First, a part (one side) of a metal pipe (element pipe) is subjected to contraction processing to form a small-diameter pipe part 3, and as shown in FIG. 1, as shown in FIG. Part 3 forms a continuous tube. The plate thickness of the small-diameter pipe portion 3 is not reduced as compared with the raw pipe by this contraction processing.
[0015]
For example, as shown in FIG. 2 (a), the tube contraction processing method includes a mold 4 having a large-diameter convex shape 4 a having the same diameter as the inner diameter of the raw tube portion 1, and the same diameter as the outer diameter of the small-diameter tube portion 3. 2b and a mold 5 having a taper concave mold 5b. As shown in FIG. 2 (b), the large diameter convex mold 4a is pressed and inserted from one end of the raw tube portion 1, and the taper concave mold 5b is inserted from the other end. Then, the small-diameter concave mold 5a is pressed and inserted to reduce the tube. In addition, this tube contraction processing may be performed by other known methods such as swaging.
[0016]
In actual production, the raw tube 1 was made of SUS409, the tube diameter D 1 was φ25.4 mm, and the plate thickness t was 1 mm. Further, in the tube contraction processing, the above-described raw tube (25.4 mm) was contracted until the diameter d became φ17 mm to form the small diameter tube portion 3.
[0017]
Next, as shown in FIG. 3, the punch 6 having the R 3 formed on the tip shoulder portion 6 a is used, the opening end side of the small-diameter tube portion 3 is fixed with the member 7, and the punch 6 is attached to the base tube portion 1. Inserted from the opening end side, a pressing load P 1 is applied to the boundary portion 1a between the raw tube portion 1 and the taper portion 2 by the radius R 3 of the tip shoulder portion 6a, and the radius R 1 is formed at the boundary portion 1a. The radius of the radius R 1 is set larger than the radius R 2 of the boundary portion 3 a between the small diameter pipe portion 3 and the taper portion 2.
[0018]
Next, as shown in FIG. 4, the open end side of the raw tube portion 1 is fixed with a member 7 a, and a compressive load P 2 is applied to the small diameter tube portion 3 to press the small diameter tube portion 3 toward the raw tube portion 1. . At this time, since radius R 1 of the boundary portion 1a of the base pipe portion 1 and the tapered portion 2 is larger than the radius R 2 of the boundary portion 3a of the small diameter tube portion 3 and the tapered portion 2, a tapered portion 2 due to the load P 2 The larger diameter side (element tube side) is buckled inward first than the small diameter side, and the taper portion 2 is prevented from bulging outward. Therefore, by continuously applying the compressive load P 2 , the taper portion 2 is continuously and continuously buckled inward from the raw tube portion 1 side, and the small-diameter tube portion 3 is bent or inclined. Instead, a three-layer tube as shown in FIG. 4 is formed.
[0019]
In addition, since the above-mentioned contraction processing, which is the preceding process, is not a tensile process, the pipe is pulled only during the buckling process, the taper portion is less brittle, and the pipe cracks due to the pulling during the buckling process. Does not occur. In addition, since the tube contraction process does not cause a reduction in the plate thickness, it is possible to prevent a decrease in the strength of the material in the tapered portion 2, which also contributes to prevention of cracking of the tube.
[0020]
At the time of the above-described tube contraction, the tube contraction process may be performed in a plurality of steps to increase the diameter reduction. For example, the above tube of φ25.4 may be reduced to d = φ17 in the first contraction step, or may be reduced to d = φ14 in the second contraction step.
[0021]
5 to 7 show the manufacturing method of the second embodiment.
In this embodiment, first, a part (one side) of a metal pipe (base pipe) is subjected to a tube-reducing process in the same manner as in the first embodiment, so that the diameter of the portion is reduced, and the other side is expanded to increase the diameter. Then, as shown in FIG. 5, a tube in which the large diameter portion 1b, the tapered portion 2 and the small diameter tube portion 3 are continuous is formed. As the tube expansion processing method, for example, the large-diameter convex mold 4a shown in FIG. 2A is made larger in diameter than the inner diameter of the raw tube, or other well-known tube expansion processing methods.
[0022]
In addition, the element tube 1 actually used as this example was the same as the element tube 1 in the first example. Further, the small diameter tube portion 3 and swaged to the first embodiment and the same d = 17 mm or 14 mm, the large-diameter pipe portion 1b was pipe expansion the diameter D 2 to Fai29.2Mm.
[0023]
Next, as shown in FIG. 6 (a), the large diameter pipe portion 1b and the taper are formed by the rounding process similar to that of the first embodiment, using the punch 8 having the rounded R 4 formed on the tip shoulder portion 8a. A round R 5 is formed at the boundary portion 1 a with the portion 2. The radius of the radius R 5 is set larger than the radius R 6 of the boundary portion 3 a between the small diameter pipe portion 3 and the taper portion 2.
At this time, as shown in FIG. 6B, if the tapered portion 2 is also expanded at the same time so that the tapered portion 2 is formed at a substantially right angle with respect to the tube axis, it is effective in the subsequent process.
[0024]
Next, as shown in FIG. 7, to secure the open end of the large diameter tubular portion 1b in member 7a, a small-diameter tube portion 3 by applying a compressive load P 4 in the small diameter tube portion 3 to the large-diameter pipe portion 1b direction Press. At this time, since R 6 <R 5 is formed, the tapered portion 2 buckles without bulging outward as in the first embodiment, and the small-diameter tube portion 3 is not bent or inclined. A three-layer tube as shown in FIG. 7 is formed.
[0025]
According to the second embodiment, the difference in diameter between the large-diameter pipe portion 1b and the small-diameter pipe portion 3 can be increased, and continuous buckling deformation easily occurs during buckling. In addition, a three-layer tube having an outer diameter D 2 of the large-diameter pipe portion 1b larger than the outer diameter D 1 of the raw tube portion 1 of the first embodiment is obtained.
[0026]
In addition, the pipe expansion rate of the large-diameter pipe portion 1b in the second embodiment is set to 15% or less so that a large pull does not occur during the pipe expansion.
Further, when the relationship between R 1 and R 2 and the relationship between R 5 and R 6 is set to R 2 <R 1 and R 6 <R 5 , the meat on the large diameter side flows buckling and buckling occurs. Progress continuously and smoothly.
[0027]
Further, the flange portion 10 as shown in FIG. 8 is bent at the opening side end of the raw tube portion 1 of the first embodiment or the large-diameter tube portion 1b of the second embodiment. A layer tube is obtained.
[0028]
Furthermore, a W-shaped four-layer tube is formed by folding the opening side portion of the raw tube portion 1 of the first embodiment or the large-diameter tube portion 1b of the second embodiment to form the outer tube portion 11. Can do. The diameter of the outer tube 11 is, for example, φ30 mm when the raw tube portion 1 is bent, and φ34.5 mm when the large-diameter tube portion 1 b is bent. Further, the flange portion 10 may be bent at the opening end side of the outer tube 11.
[0029]
In addition, the length of the pipe | tube of each layer in each said Example is set as desired, and the length is set as desired by setting the length of the taper part 2, buckling length, bending length, etc. as desired. Can be adjusted.
[0030]
The multilayer pipe manufactured according to the present invention is used for, for example, a pipe forming an EGR port of a resin intake manifold in an internal combustion engine, and is connected to the intake manifold or the like by the flange portion 10 shown in FIGS. Is done.
[0031]
【The invention's effect】
As described above, according to the first aspect of the present invention, the buckling to the inside of the taper portion and the raw tube portion is performed smoothly and continuously during buckling, and the bending of the small diameter tube portion Inclination is prevented, and an ideal bent-inverted multilayer tube can be manufactured. Furthermore, there is no occurrence of cracks in the tube.
[0032]
According to the second aspect of the present invention, continuous buckling deformation is more likely to occur, and the manufacture of the multilayer tube is facilitated.
According to the third aspect of the present invention, the rounding process of the boundary portion can be easily performed with a simple structure.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a tube illustrating a contraction step in the manufacturing method according to the first embodiment of the present invention.
2A is a cross-sectional view showing a die used in the contraction process of FIG. 1, and FIG. 2B is a view showing a processing state thereof.
FIG. 3 is a cross-sectional view of a pipe showing a rounding process after the step of FIG. 1;
4 is a cross-sectional view of a tube showing a buckling step after the step of FIG. 3;
FIG. 5 is a cross-sectional view of a tube showing a contraction tube and a tube expansion step in the manufacturing method of the second embodiment of the present invention.
6A is a cross-sectional view of a pipe showing a rounding process after the process of FIG. 5, and FIG. 6B is an example in which the taper portion is bent at a substantially right angle to the pipe axis simultaneously with the rounding process. The principal part expanded sectional view which shows.
7 is a cross-sectional view of a tube showing a buckling step after the step of FIG. 6;
8 is a cross-sectional view of a multilayer tube in which a flange portion is formed on the multilayer tube of FIG. 4 or FIG.
9 is a cross-sectional view of a multilayer tube in which the outer tube end of the multilayer tube of FIG. 4 or FIG. 7 is flange-formed and the outer tube is further bent.
FIG. 10 is a cross-sectional view of a tube showing a first example of a conventional manufacturing method.
FIG. 11 is a cross-sectional view of a pipe expanded by showing a second example of a conventional manufacturing method.
12 is an enlarged cross-sectional view of a main part showing a buckled state of the taper portion due to pressurization of the pipe of FIG. 11;
13 is a cross-sectional view showing the bending of the tube due to the pressurization of the tube of FIG. 11. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Elementary pipe part 1a, 3a ... Boundary part 1b ... Large diameter pipe part 2 ... Tapered part 3 ... Small diameter pipe part 6, 8 ... Punch 6a, 8a ... Tip shoulder part

Claims (3)

素管の一部に縮管加工を施して素管部とテーパ部と小径管部を連続状態に形成する縮管工程と、素管部とテーパ部の境界部のアールを小径管部とテーパ部の境界部のアールよりも大きくするアール付け工程と、素管部と小径管部が相互に近づく方向へ押圧してテーパ部を順次座屈させる座屈工程とからなることを特徴とする多層管の製造方法。A contraction process is performed in which a part of the raw pipe is subjected to contraction processing to form the raw pipe part, the taper part, and the small diameter pipe part in a continuous state, and the radius of the boundary between the raw pipe part and the taper part is reduced to the taper of the small diameter pipe part. A multi-layered structure comprising a rounding process for making the radius larger than the rounded corner of the boundary part and a buckling process for sequentially buckling the taper part by pressing the raw pipe part and the small-diameter pipe part toward each other. A method of manufacturing a tube. アール付け工程前に、素管部を拡張して大径部に形成する工程を有する請求項１記載の多層管の製造方法。The manufacturing method of the multilayer pipe | tube of Claim 1 which has the process of expanding a raw pipe part and forming in a large diameter part before a rounding process. アール付け工程において、先端肩部にアール部を有するパンチを素管部又は大径管部とテーパ部との境界部の内面に押圧して、その境界部をパンチのアール部でアール付け加工を施すようにした請求項１又は２記載の多層管の製造方法。In the rounding process, the punch having the rounded portion at the tip shoulder is pressed against the inner surface of the boundary portion between the raw tube portion or the large-diameter pipe portion and the taper portion, and the border portion is rounded with the rounded portion of the punch. The method for producing a multilayer tube according to claim 1 or 2, wherein the method is applied.
JP25152497A 1997-09-17 1997-09-17 Manufacturing method of multilayer pipe Expired - Lifetime JP4021976B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25152497A JP4021976B2 (en) 1997-09-17 1997-09-17 Manufacturing method of multilayer pipe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25152497A JP4021976B2 (en) 1997-09-17 1997-09-17 Manufacturing method of multilayer pipe

Publications (2)

Publication Number Publication Date
JPH1182824A JPH1182824A (en) 1999-03-26
JP4021976B2 true JP4021976B2 (en) 2007-12-12

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Publication number Priority date Publication date Assignee Title
JP5932302B2 (en) * 2011-11-14 2016-06-08 フタバ産業株式会社 Tube end forming method
CN107824631B (en) * 2017-11-28 2024-03-19 华中科技大学 Forming device and method for stainless steel double-layer pipe

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