JPS5893516A - Hot bending method for pipe - Google Patents

Hot bending method for pipe

Info

Publication number
JPS5893516A
JPS5893516A JP19088381A JP19088381A JPS5893516A JP S5893516 A JPS5893516 A JP S5893516A JP 19088381 A JP19088381 A JP 19088381A JP 19088381 A JP19088381 A JP 19088381A JP S5893516 A JPS5893516 A JP S5893516A
Authority
JP
Japan
Prior art keywords
pipe
bending
coil
heating coil
bent
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.)
Granted
Application number
JP19088381A
Other languages
Japanese (ja)
Other versions
JPH0261335B2 (en
Inventor
Hiroshi Asao
浅尾 宏
Kenichi Okada
健一 岡田
Noboru Umehara
昇 梅原
Hideo Yonemura
米村 秀雄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP19088381A priority Critical patent/JPS5893516A/en
Publication of JPS5893516A publication Critical patent/JPS5893516A/en
Publication of JPH0261335B2 publication Critical patent/JPH0261335B2/ja
Granted legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21DWORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D7/00Bending rods, profiles, or tubes
    • B21D7/02Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment
    • B21D7/024Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment by a swinging forming member
    • B21D7/025Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment by a swinging forming member and pulling or pushing the ends of the work

Abstract

PURPOSE:To suppress a decrease in the thickness of a bent part by specifying the shape and outside coil gap of a high-frequency induction heating coil arranged at the outer circumference of the bent part of a pipe. CONSTITUTION:A pipe 1 is placed between guide rolls 9; one end is clamped by a rotary arm 5, and the other is coupled with a pusher 7. A heating coil 2A is set at the outer circumference of a bent part of the pipe 1. In this case, the coil 2A is elliptic, the long diameter 2c is set in a bending plane, and external and internal coil gaps 2a and 2b of bending are so specified that 2a>2b. Then, a high frequency oscillator 11 is powered on to heat the pipe 1 through the coil 2A, and a heated area is suppressed to a necessary range by cooling water spouted out of a cooling ring 10. When a dichromatic thermometer 3 detects prescribed temperature, a pusher 7 loads pressure 4 and then the pipe 1 is guided around a pivot 6 with a prescribed radius of bending, thus performing hot bending. In this case, the internal part is at higher temperature than the external part, so a decrease in the thickness of the external part is reduced.

Description

【発明の詳細な説明】 本発明は、パイプの熱間曲げ加工法に係シ、特に曲げ加
工部の減肉抑止を志向した、高周波誘導加熱、を利用し
た、パイプの熱間曲げ加工法に関するものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for hot bending a pipe, and more particularly, to a method for hot bending a pipe using high-frequency induction heating aimed at suppressing thinning of the bent portion. It is something.

まず従来の、高周波誘導加熱を利用したパイプの熱間曲
げ加工法の概要と、その問題点を、第1〜3図を使用し
て説明する。
First, an overview of the conventional hot bending method for pipes using high-frequency induction heating and its problems will be explained using FIGS. 1 to 3.

第1図は、従来の、高周波誘導加熱を利用したパイプの
熱間曲げ加工法の実施に供せられる装置の概要を示す平
面図、第2図は、第1図の■−■断面図、第3図は、従
来の、パイプの熱間曲げ加工法による、パイプの曲げ半
径比と減肉率との関係を示す曲げ半径比−減肉率特性図
である。
FIG. 1 is a plan view showing an outline of a device used to perform a conventional hot bending method for pipes using high-frequency induction heating, and FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. FIG. 3 is a bending radius ratio-thickness reduction rate characteristic diagram showing the relationship between the bending radius ratio and the thickness reduction rate of a pipe according to a conventional hot bending method for pipes.

第1図において1は、曲げ加工すべきパイプ、2は、パ
イプlの曲げ加工部の外周に配設された真円形状の加熱
コイルである。たとえば、パイプ1の外径Do=90m
φ、加熱コイル2の内径100Wφ、コイルギャップ5
 ws (円周上均一)である。5は、パイプ1の一端
をクランプし、ピボット6を中心に自在に回転できる回
転アーム、9は、パイプ1を支持し、パイプ1の移動方
向を直進方向に規制するガイドロールである。
In FIG. 1, reference numeral 1 indicates a pipe to be bent, and reference numeral 2 indicates a perfectly circular heating coil disposed around the outer periphery of the bending portion of the pipe I. For example, the outer diameter Do of pipe 1 is 90 m
φ, inner diameter of heating coil 2 100Wφ, coil gap 5
ws (uniform on the circumference). 5 is a rotary arm that clamps one end of the pipe 1 and can freely rotate around a pivot 6; 9 is a guide roll that supports the pipe 1 and restricts the moving direction of the pipe 1 to the straight direction.

このように構成した、第1図に係る装置による、従来の
パイプの熱間曲げ加工法によれば、パイプ1は真円形状
の加熱コイル2によって円周方向に均熱される。均熱す
ることにより、パイプ1の平均変形抵抗を小さく抑え、
加工力を低下させ、加熱した状態でパイプ1の軸方向に
加工力4を負荷することによって回転アーム5をピボッ
ト6のまわりに回転させ、パイプ1の曲げ加工を行なう
ことができる。
According to the conventional pipe hot bending method using the apparatus shown in FIG. 1, which is configured as described above, the pipe 1 is uniformly heated in the circumferential direction by the perfectly circular heating coil 2. By uniformly heating, the average deformation resistance of pipe 1 is kept low,
By lowering the working force and applying a working force 4 in the axial direction of the pipe 1 in a heated state, the rotary arm 5 is rotated around the pivot 6, and the pipe 1 can be bent.

しかし上記した従来技術によれば、パイプlの曲は外側
部1aは、前記加工力4により発生する軸方向引張応力
によって減肉する(曲げ内側部1bは、逆に増肉する)
。とくに、曲げ半径rを小さくすると、減肉率が大きく
表る。
However, according to the above-mentioned conventional technology, the outside part 1a of the curved pipe 1 is thinned by the axial tensile stress generated by the working force 4 (on the contrary, the thickness of the bent inside part 1b is increased).
. In particular, when the bending radius r is made small, the rate of thickness reduction becomes large.

減肉率=(to  t)/1xxo、o%ただしto 
:曲げ加工前のパイプの板厚t :曲げ加工後のパイプ
の板厚 たとえば、r =−1,5Do 17)場合、第3図か
ら明らかなように、減肉率が19%となシ、耐圧特性を
考慮した減肉率の要求仕様12−5%以下を満足するこ
とができないという欠点があった。
Thickness reduction rate = (to t)/1xxo, o% but to
: Thickness of the pipe before bending t : Thickness of the pipe after bending For example, r = -1,5 Do 17) As is clear from Fig. 3, the thinning rate is 19%. There was a drawback that it was not possible to satisfy the required specification of the thinning rate of 12-5% or less in consideration of pressure resistance characteristics.

本発明は、上記した従来技術の欠点を除去して、曲げ加
工部の減肉を抑止することができる、高周波誘導加熱を
利用した、パイプの熱間曲げ加工法の提供を、その目的
とするものである。
An object of the present invention is to provide a method for hot bending a pipe using high-frequency induction heating, which can eliminate the drawbacks of the prior art described above and prevent thinning of the bent portion. It is something.

本発明の特徴は、パイプの曲げ加工部の外周に加熱コイ
ルを配設し、この加熱コイルで前記曲げ加工部を高周波
誘導加熱しながら、前記パイプを曲げ加工するようにし
たパイプの熱間聞げ加工法において、加熱コイルを、長
円形状の加熱コイルとし、この加熱コイルを、曲げ外側
のコイルギャップが曲げ内側のコイルギャップよシも大
きくなるように配設した、パイプの熱間曲げ加工法にあ
る。
A feature of the present invention is that a heating coil is disposed around the outer periphery of the bending portion of the pipe, and the pipe is bent while the heating coil is heating the bending portion using high-frequency induction. In the bending method, the heating coil is an elliptical heating coil, and the heating coil is arranged so that the coil gap on the outside of the bend is larger than the coil gap on the inside of the bend. It's in the law.

さらに詳しくは、加熱コイルの形状を長円形状とし、且
つコイル位置制御装置を設け、パイプの曲げ加工部の減
肉側(曲げ外側部)のコイルギヤ・::・ニ ツブを大きく、増肉側(曲げ内側部)を小さくし、前記
パイプの円周方向に温度分布を与え、変形抵抗に勾配を
つけることにより、゛曲げ中立軸を減肉側(曲げ外側部
)へ移行させ、減肉を抑止するようにしたものである。
More specifically, the shape of the heating coil is made into an ellipse, and a coil position control device is provided. By reducing the bending (inner side), providing a temperature distribution in the circumferential direction of the pipe, and creating a gradient in deformation resistance, the bending neutral axis is shifted to the thinning side (bending outer side) and thinning is suppressed. It was designed to do so.

以下本発明を実施例によって説明する。The present invention will be explained below with reference to Examples.

第4図は、本発明の一実施例に係る、パイプの熱間曲げ
加工法の実施に供せられる装置の一例と、これによって
曲げ刀ロエされるパイプを併せて示す平面図、第5図は
、第4図における加熱コイル近傍の詳細を示す平面図、
第6図は、第5図の■−■断面図である。
FIG. 4 is a plan view showing an example of a device used to carry out a hot bending method for pipes according to an embodiment of the present invention, together with a pipe that is bent with a bending knife, and FIG. is a plan view showing details of the vicinity of the heating coil in FIG. 4;
FIG. 6 is a sectional view taken along the line ■-■ in FIG. 5.

第4図において、1は、曲げ加工すべきパイプ、5は、
パイプ1の一端をクランプし、ピボット6を中心に自在
に回転できる回転アーム、7は、パイプ1の他端に結合
されたブツシャ、8は、ブツシャ7を介して、パイプ1
に軸方向の加工力4を負荷するための油圧シリンダ、9
は、パイプ1を支持し、パイプ1の移動方向を直進方向
に規制するガイドロールである。2人は、第6図にその
詳細を示すように、長円形状の加熱コイル(2Cは長径
、2dは短径)であり、この加熱コイル2人は、曲げ外
側のコイルギャップ2aが曲げ内側のコイルギャップ2
bよシも大きくなるように、パイプ1の曲げ加工部の外
周に配設されている。そして、この加熱コイル2人には
、パイプ1の曲げ中立部の温度(ここの温度は、パイプ
1の加熱領域の平均温度にほぼ等しい)を、非接触で検
出する二色温度計3が装着されている。11は、加熱コ
イル2人に高周波電流を供給する高周波発振機、10は
、加熱コイル2人による加熱領域が曲げ加工に必要な領
域以上になることを抑制するために、パイプ1に向けて
冷却水を噴射する冷却リングであシ、この冷却リング1
0は、加熱コイル2人の前後(第4図において左右方向
)に配設されている。
In FIG. 4, 1 is a pipe to be bent, 5 is
A rotary arm that clamps one end of the pipe 1 and can freely rotate around a pivot 6; 7 is a button coupled to the other end of the pipe 1;
a hydraulic cylinder for applying an axial machining force 4 to the
are guide rolls that support the pipe 1 and restrict the moving direction of the pipe 1 to the straight direction. As shown in detail in Fig. 6, the two heating coils are oval shaped heating coils (2C is the major axis, 2d is the minor axis), and the coil gap 2a on the outside of the bend is on the inside of the bend. Coil gap 2
It is arranged around the outer periphery of the bent portion of the pipe 1 so that the width is also large. These two heating coils are equipped with a two-color thermometer 3 that non-contact detects the temperature of the bending neutral part of the pipe 1 (the temperature here is approximately equal to the average temperature of the heating area of the pipe 1). has been done. 11 is a high-frequency oscillator that supplies high-frequency current to the two heating coils; 10 is a high-frequency oscillator that supplies cooling toward the pipe 1 in order to prevent the area heated by the two heating coils from exceeding the area necessary for bending; A cooling ring that injects water, this cooling ring 1
The heating coils 0 are arranged in front and behind the two people (in the left-right direction in FIG. 4).

このように構成した、第4図に係る装置による、パイプ
の熱間曲げ加工法を説明する。
A method of hot bending a pipe using the apparatus shown in FIG. 4 configured as described above will be explained.

まず、パイプ1(外径])o=90■φ、板厚4■の炭
素鋼)をガイドロール9の間に置き、その一端を回転ア
ーム5にクランプし、他端をブツシャ7に結合する。パ
イプlの曲げ加工部の外周に、沖熱コイル2人およびそ
の前後に冷却リング10をセツティングする。前記加熱
コイル2人は、長径2C(内径”)が1105gm、短
径2d(内径)が100mの長円形状であり、長径2C
を曲げの面内に置き、曲げ外側のコイルギャップ2aが
15■1曲i内側のコイルギャップ2bが5簡になるよ
うに配設する。
First, a pipe 1 (outer diameter) o = 90 mm φ, plate thickness 4 mm carbon steel) is placed between the guide rolls 9, one end of which is clamped to the rotating arm 5, and the other end is connected to the bushing 7. . Two Oki thermal coils and a cooling ring 10 are set on the outer periphery of the bent portion of the pipe 1. The two heating coils have an oval shape with a major axis 2C (inner diameter) of 1105 gm and a minor axis 2d (inner diameter) of 100 m.
is placed in the plane of the bend, and arranged so that the coil gap 2a on the outside of the bend is 15 cm, and the coil gap 2b on the inside of the bend is 5 cm.

高周波発振機11に通電し、その出力を、加熱コイル2
人を介してパイプ1に入力する。高周波により加熱コイ
ル2人の近傍に生じた交番磁界でパイプ1に誘導電流が
流れ、パイプ1内のオーム損により発熱する。そして、
冷却リング10からパイプ1に向けて冷却水を噴射し、
パイプ1の加熱領域が必要な郷域以上(加熱領域が過度
に拡がると、パイプ1が座屈する)になるのを抑制する
The high frequency oscillator 11 is energized and its output is transmitted to the heating coil 2.
Input to pipe 1 via a person. An induced current flows through the pipe 1 due to the alternating magnetic field generated near the two heating coils by high frequency, and heat is generated due to ohmic loss within the pipe 1. and,
Injecting cooling water from the cooling ring 10 toward the pipe 1,
The heating area of the pipe 1 is suppressed from exceeding a required area (if the heating area expands excessively, the pipe 1 will buckle).

二色温度計3の検出値が所定の温度まで上昇したら、加
熱した状態でパイプ1の軸方向に油圧シリンダ8によシ
プツシャ7を介しτ加エカ4を負荷する。しかし、一端
が回転グー15にクランプされているため、パイプ1は
ピボット6のまわシを所定の曲げ半径r (=1.5D
o =135sag)セ誘導される。これによシ発生し
た曲げモーメントによシバイブ1が熱間曲げ加工される
When the detected value of the two-color thermometer 3 rises to a predetermined temperature, a τ stress 4 is applied to the hydraulic cylinder 8 in the axial direction of the heated pipe 1 via the pusher 7. However, since one end is clamped to the rotary goo 15, the pipe 1 bends around the pivot 6 with a predetermined bending radius r (=1.5D
o = 135sag) is induced. The bending moment generated thereby causes the vibrator 1 to undergo hot bending.

この熱間曲げ加工時、パイグーの曲げ外側部1aの温度
は600C,曲げ内側部1bの温度は900Cとなり(
曲げ内側部1bの方がコイルギャップ2bが小さいため
高温になる)、それぞれの変形抵抗は11Kgf/m”
 、5Kff/w”とな゛るので、晶げ中立軸は、パイ
プ−の中心から外側へ移動する。
During this hot bending process, the temperature of the outer bending part 1a of the pai goo is 600C, and the temperature of the bending inner part 1b is 900C (
The bending inner part 1b has a smaller coil gap 2b, so the temperature is higher), and the deformation resistance of each part is 11Kgf/m"
, 5Kff/w'', the neutral axis of crystallization moves outward from the center of the pipe.

このようにして熱間曲げ加工されたパイグーの曲げ外側
部1aの減肉率は、従来の加工法では19%であったも
のが、本実施例では、11%に低減し、要求仕様12,
5%以下を満足することができる。
The thickness reduction rate of the bent outer part 1a of the pai goo hot bent in this way was 19% in the conventional processing method, but in this example, it was reduced to 11%, and the required specification 12,
5% or less can be satisfied.

第7図は、本発明の他の実施例に係る、パイプの熱間曲
げ加工法の実施に供せられる装置の要部の一例と、これ
によって曲げ加工されるパイプを′:: 併せて示す平面図である。
FIG. 7 shows an example of a main part of an apparatus used for carrying out a hot bending method for pipes according to another embodiment of the present invention, and also shows a pipe to be bent by the apparatus. FIG.

この第7図において、第4図と同一番号を付したものは
同一部分である。そして、3Aは、加熱コイル2Bに装
着された、パイプ−の曲げ外側部1aの温度を非接触で
測定する二色温度計、12は、二色温度計3A(7)’
検出値に基づいて、パイプ1の曲げ外側部1aの温度が
予め設定した設定温度になるように、コイルギャップ2
aを調整して、加熱コイル2Bの位置を制御することが
できるコイル位置制御装置である。冷却リング10は、
冷却効果を変動させることのないよう、一定の位置に固
定されている。
In FIG. 7, the same parts as those in FIG. 4 are denoted by the same numbers. 3A is a two-color thermometer that is attached to the heating coil 2B and measures the temperature of the bent outer part 1a of the pipe without contact; 12 is a two-color thermometer 3A (7)'
Based on the detected value, the coil gap 2 is adjusted so that the temperature of the bent outer part 1a of the pipe 1 reaches a preset temperature.
This is a coil position control device that can control the position of the heating coil 2B by adjusting a. The cooling ring 10 is
It is fixed in a fixed position so that the cooling effect does not fluctuate.

このように構成したので、パイプ1の曲げ加工中、パイ
プ1の曲げ外側部1aの温度を常に一定に保持する°こ
とができ、したがって減肉率も安定するので、第4図に
係る実施例よりも、さらに安定したパイプの熱間曲げ加
工が可能になる。−以上説明した各実施例によれば、パ
イプ1の曲げ加工部の減肉を抑止でき、大幅に加工限界
を向上させることができる。すなわち、曲げ加工部の減
肉率を12.5%以下に押え得る最小曲げ半径rを、従
来の3.0Do  (Do  ”パイプの外径)から、
1.5Doまで小径化でき、成形品の形状のコンパクト
化に大きく寄与するものである。
With this structure, the temperature of the bent outer part 1a of the pipe 1 can be kept constant during the bending process of the pipe 1, and the thinning rate is also stabilized, so that the embodiment according to FIG. This enables more stable hot bending of pipes. - According to each of the embodiments described above, thinning of the bending portion of the pipe 1 can be suppressed, and the processing limit can be significantly improved. In other words, the minimum bending radius r that can suppress the wall thinning rate of the bent part to 12.5% or less is determined from the conventional 3.0 Do (Do '' outside diameter of the pipe).
The diameter can be reduced to 1.5 Do, which greatly contributes to making the shape of the molded product more compact.

以上詳細に説明したように本発明によれば、ノ;イブの
曲げ加工部の外周に加熱コイルを配設し、この加熱コイ
ルで前記曲げ加工部を高周波誘導カロ熱しながら、前記
パイプを曲げ加工するようにしたパイプの熱間曲げ加工
法において、カロ熱コイルを、長円形状の加熱コイルと
し、この加熱コイルを、曲げ外側のコイルギャップが曲
げ内側のコイルギャップよシも大きくなるように配設し
たので、曲げ加工部の減肉を抑止することができる、高
周波誘導加熱を利用した、ノ(イブの熱間曲げ加工法を
提供することができる。  、
As explained in detail above, according to the present invention, a heating coil is disposed around the outer periphery of the bending portion of the pipe, and the heating coil is used to heat the bending portion with high-frequency induction heating while bending the pipe. In the hot bending method for pipes, the Calo heating coil is an elliptical heating coil, and this heating coil is arranged so that the coil gap on the outside of the bending is larger than the coil gap on the inside of the bending. As a result, it is possible to provide a hot bending method using high-frequency induction heating, which can suppress thinning of the bent part.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は、従来の、高周波誘導加熱を利用したパイプの
熱間曲げ加工法の実施に供せられる装置の概要を示す平
面図、第2図は、第1図の■−IF断面図、第3図は、
従来の、・クイズの熱間曲げjyロ工法による、パイプ
の曲げ半径比と減肉率との関係を示す曲げ半径比−減肉
率特性図、第4図は、本発明の一実施例に係る、)<イ
ブの熱間曲げ加工法の実施に供せられる装置の一例と、
これによつて曲げ加工されるパイプを併せて示す平面図
、第5図は、第4図における加熱コイル近傍の詳細を示
す平面図、第6図は、第5図の’%I−vt断面図、′
第7図は、本発明の他の実施例に係る、パイプの熱間曲
げ加工法の実施に供せられる装置の要部の一例と、これ
によって曲げ加工されるパイプを併せて示す平面図であ
る。 1・・・パイプ、1a・・・パイプの曲げ外側部、1b
・・・パイプの曲げ内側部、2A、2B・・・加熱コイ
ル、2a・・・曲げ外側のコイルギャップ、2b・・・
曲げ内側のコイルギャップ、2C・・・加熱コイルの長
径、2d・・・加熱コイルの短径、3,3A・・・二色
温度計、11・・・高周波発振機、12・・・コイル位
置制御装置。 (ほか1名)3卒 手I 目 J1!2目 ls  目 四ケ゛辛短比()) 訂= Jlt4−Iib2A /JL。 ゴ メ冊
FIG. 1 is a plan view showing an outline of a device used to carry out a conventional hot bending method for pipes using high-frequency induction heating, and FIG. 2 is a sectional view taken along the line IF in FIG. Figure 3 shows
FIG. 4 is a bending radius ratio-thickening rate characteristic diagram showing the relationship between the bending radius ratio and the thinning rate of a pipe according to the conventional hot bending method of Quiz. An example of a device used to carry out the hot bending method of )
FIG. 5 is a plan view showing details of the vicinity of the heating coil in FIG. 4, and FIG. 6 is a '%I-vt section in FIG. figure,'
FIG. 7 is a plan view showing an example of a main part of an apparatus used for carrying out a hot bending method for pipes according to another embodiment of the present invention, together with a pipe to be bent by the apparatus; be. 1...Pipe, 1a...Bending outer part of pipe, 1b
...Bending inner side of pipe, 2A, 2B... Heating coil, 2a... Coil gap on the outside of bending, 2b...
Coil gap on the inside of the bend, 2C... Long diameter of the heating coil, 2d... Short diameter of the heating coil, 3, 3A... Two color thermometer, 11... High frequency oscillator, 12... Coil position Control device. (1 other person) 3rd grade hand I eye J1! 2nd eye ls eye 4 ka゛shin short ratio ()) Edit = Jlt4-Iib2A /JL. gome book

Claims (1)

【特許請求の範囲】 1、パイプの曲げ加工部の外周に加熱コイルを配設し、
この加熱コイルで前記曲げ加工部を高周波誘導加熱しな
がら、前記パイプを曲げ加工するようにしたパイプの熱
間曲げ加工法において、加熱コイルを、長円形状の加熱
コイルとし、この加熱コイルを、曲げ外側のコイルギャ
ップが曲げ内側のコイルギャップよりも大きくなるよう
に配設したことを特徴とするパイプの熱間曲げ加工法。 2、パイプの曲げ加工中、前記パイプの曲げ外側部の温
度が、予め設定した設定温度になるように、加熱コイル
のコイルギヤ′ツブを調整するようにしたものである特
許請求の範囲第1項記載のパイプの熱間曲げ加工法。
[Claims] 1. A heating coil is arranged around the outer circumference of the bent portion of the pipe,
In a hot pipe bending method in which the pipe is bent while the bending portion is heated by high-frequency induction using this heating coil, the heating coil is an elliptical heating coil, and the heating coil is A method for hot bending a pipe, characterized in that the coil gap on the outside of the bend is larger than the coil gap on the inside of the bend. 2. During the bending process of the pipe, the coil gear knob of the heating coil is adjusted so that the temperature of the outside part of the bent pipe becomes a preset temperature. Hot bending method for pipes described.
JP19088381A 1981-11-30 1981-11-30 Hot bending method for pipe Granted JPS5893516A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP19088381A JPS5893516A (en) 1981-11-30 1981-11-30 Hot bending method for pipe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19088381A JPS5893516A (en) 1981-11-30 1981-11-30 Hot bending method for pipe

Publications (2)

Publication Number Publication Date
JPS5893516A true JPS5893516A (en) 1983-06-03
JPH0261335B2 JPH0261335B2 (en) 1990-12-19

Family

ID=16265324

Family Applications (1)

Application Number Title Priority Date Filing Date
JP19088381A Granted JPS5893516A (en) 1981-11-30 1981-11-30 Hot bending method for pipe

Country Status (1)

Country Link
JP (1) JPS5893516A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1985000023A1 (en) * 1983-06-16 1985-01-03 Enaco (Australia) Pty. Ltd. Pipe deforming method and apparatus
JPS60180623A (en) * 1984-02-29 1985-09-14 Hitachi Ltd Method and device for bending metallic pipe
JPS63171220A (en) * 1987-01-08 1988-07-15 Nippon Steel Corp Method for bending steel pipe
JP5403071B2 (en) * 2010-01-06 2014-01-29 新日鐵住金株式会社 Induction heating coil, processing device manufacturing apparatus and manufacturing method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53135870A (en) * 1977-04-30 1978-11-27 Daiichi Koshuha Kogyo Kk Thin wall preventive at metal pipe bending
JPS55144332A (en) * 1979-04-26 1980-11-11 Dai Ichi High Frequency Co Ltd Bending process of metal pipe
JPS55158835A (en) * 1979-05-29 1980-12-10 Mitsubishi Heavy Ind Ltd Pipe bending method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53135870A (en) * 1977-04-30 1978-11-27 Daiichi Koshuha Kogyo Kk Thin wall preventive at metal pipe bending
JPS55144332A (en) * 1979-04-26 1980-11-11 Dai Ichi High Frequency Co Ltd Bending process of metal pipe
JPS55158835A (en) * 1979-05-29 1980-12-10 Mitsubishi Heavy Ind Ltd Pipe bending method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1985000023A1 (en) * 1983-06-16 1985-01-03 Enaco (Australia) Pty. Ltd. Pipe deforming method and apparatus
JPS60180623A (en) * 1984-02-29 1985-09-14 Hitachi Ltd Method and device for bending metallic pipe
JPH0235609B2 (en) * 1984-02-29 1990-08-13 Hitachi Ltd
JPS63171220A (en) * 1987-01-08 1988-07-15 Nippon Steel Corp Method for bending steel pipe
JP5403071B2 (en) * 2010-01-06 2014-01-29 新日鐵住金株式会社 Induction heating coil, processing device manufacturing apparatus and manufacturing method

Also Published As

Publication number Publication date
JPH0261335B2 (en) 1990-12-19

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