JP2020185572A - Method of manufacturing differential thickness tube and manufacturing device of differential thickness tube - Google Patents

Method of manufacturing differential thickness tube and manufacturing device of differential thickness tube Download PDF

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JP2020185572A
JP2020185572A JP2019089725A JP2019089725A JP2020185572A JP 2020185572 A JP2020185572 A JP 2020185572A JP 2019089725 A JP2019089725 A JP 2019089725A JP 2019089725 A JP2019089725 A JP 2019089725A JP 2020185572 A JP2020185572 A JP 2020185572A
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manufacturing
pipe
sleeve
tube
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JP7180527B2 (en
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奈沙 河越
Nasa Kawagoe
奈沙 河越
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Nippon Steel Corp
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Abstract

To provide a method of manufacturing a differential thickness tube and a manufacturing device of a differential thickness tube that can flexibly accommodate a wide variety of processing conditions.SOLUTION: A method of manufacturing a differential thickness tube is for manufacturing a differential thickness tube P from a hollow tubular element tube W, and comprises: a locking step of arranging the element tube W in a die 10, pushing in a plug body 30 together with a sleeve 40 from one end Wa side of the element tube while regulating movement of the element tube W in a longer direction, forming an expanded-shaped part 1c with an external shape on the one end Wa side expanded, and locking the expanded-shaped part 1c to the die 10; and a squeezing processing step of further pushing in the plug body 30 toward the other end Wb side of the element tube W with the locking of the element tube W released while the regulation of the element tube W is maintained and with an inner surface of the expanded-shaped part 1c supported by the sleeve 40, and performing squeezing processing for expanding an inner shape while maintaining an external shape of the element W.SELECTED DRAWING: Figure 1

Description

この発明は、差厚管の製造方法と、差厚管の製造装置と、に関する。 The present invention relates to a method for manufacturing a differential thickness tube and an apparatus for manufacturing a differential thickness tube.

自動車の車体を構成する部材として、衝突等により受けた衝突エネルギーを自らが潰れることによって吸収する部分と、潰れずに車体を保護する部分と、を有するものが用いられている。このような部材の一つとして、長手方向に沿って肉厚が異なる差厚管がある。 As a member constituting the vehicle body of an automobile, a member having a portion that absorbs collision energy received by a collision or the like by being crushed by itself and a portion that protects the vehicle body without being crushed is used. As one of such members, there is a differential thickness pipe having a different wall thickness along the longitudinal direction.

差厚管の製造方法の一例が、特許文献1に開示されている。
特許文献1の図1には、係止工程としごき加工工程とを有する差厚管の製造方法が開示されている。前記係止工程では、素管をダイス内に配置し、前記素管の長手方向への移動を規制した状態で、前記素管の一端部側よりプラグを押し込んで前記一端部側の外形を拡大させて前記ダイスに係止させる。続く前記しごき加工工程では、前記素管の前記規制を解く一方、前記素管の前記係止は維持したまま、前記プラグをさらに前記素管の他端部側に向かって押し込むことで、前記素管の外形を維持したまま内形を拡げるしごき加工を加えて薄肉部を形成する。
上記特許文献1に記載の製造方法によれば、差厚管を容易に製造できる。
An example of a method for manufacturing a differential thickness tube is disclosed in Patent Document 1.
FIG. 1 of Patent Document 1 discloses a method for manufacturing a differential pipe having a locking step and an ironing process. In the locking step, the raw pipe is arranged in the die, and the plug is pushed from one end side of the raw pipe in a state where the movement of the raw pipe in the longitudinal direction is restricted, and the outer shape of the one end side is enlarged. And lock it to the die. In the subsequent ironing process, the regulation of the raw pipe is released, and the plug is further pushed toward the other end side of the raw pipe while maintaining the locking of the raw pipe. A thin part is formed by ironing to expand the inner shape while maintaining the outer shape of the pipe.
According to the manufacturing method described in Patent Document 1, the differential thickness tube can be easily manufactured.

特許第6256668号公報Japanese Patent No. 6256668

一方、差厚管を自動車に幅広く適用するためには、素管内外面とダイス及びプラグとの間の摩擦係数や、必要とされるしごき率などの加工条件に幅広く対応できる製造方法や装置が求められていた。 On the other hand, in order to widely apply the differential thickness pipe to automobiles, a manufacturing method and equipment that can widely meet the processing conditions such as the friction coefficient between the inner and outer surfaces of the raw pipe and the die and the plug and the required ironing rate are required. Was being done.

本発明は、上記事情に鑑みてなされたものであって、幅広い加工条件に応じて柔軟に対応できる、差厚管の製造方法と、差厚管の製造装置との提供を課題とする。 The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a differential thickness tube and an apparatus for manufacturing a differential thickness tube, which can flexibly respond to a wide range of processing conditions.

上記課題を解決して係る目的を達成するために、本発明は以下の手段を採用している。
(1)本発明の一態様に係る差厚管の製造方法は、中空筒状の素管より差厚管を製造する方法であって、前記素管をダイス内に配置し、前記素管の長手方向への移動を規制した状態で、前記素管の一端側よりプラグ本体をスリーブと共に押し込み、前記一端側の外形を拡大させた拡形部を形成し、前記拡形部を前記ダイスに係止させる係止工程と;前記素管の前記規制を解く一方で前記素管の前記係止は維持してかつ、前記拡形部の内面を、前記スリーブで支えた状態で、前記プラグ本体をさらに前記素管の他端側に向かって押し込み、前記素管の外形を維持したまま内形を拡げるしごき加工を行う、しごき加工工程と;を有する。
In order to solve the above problems and achieve the object, the present invention employs the following means.
(1) The method for manufacturing a differential thickness tube according to one aspect of the present invention is a method for producing a differential thickness tube from a hollow tubular raw tube, in which the raw tube is arranged in a die and the raw tube is formed. With the movement in the longitudinal direction restricted, the plug body is pushed together with the sleeve from one end side of the raw pipe to form an enlarged portion with an enlarged outer shape on the one end side, and the enlarged portion is engaged with the die. The locking step of stopping the plug body; while releasing the restriction of the raw pipe, the locking of the raw pipe is maintained, and the inner surface of the enlarged portion is supported by the sleeve. Further, it has a squeezing process of pushing toward the other end side of the raw tube and performing an squeezing process to expand the inner shape while maintaining the outer shape of the raw tube.

(2)上記(1)に記載の差厚管の製造方法において、以下のようにしてもよい:前記係止工程で、前記拡形部に、前記プラグ本体の押し込み方向に向かって外形が先細りとなるテーパー部が形成され;前記しごき加工工程で、少なくとも、前記素管の前記一端側より前記テーパー部の前記押し込み方向に沿った後端位置までの範囲における前記拡形部の内面を、前記スリーブにより支える。 (2) In the method for manufacturing a differential thick tube according to (1) above, the following may be performed: In the locking step, the outer shape of the enlarged portion is tapered in the pushing direction of the plug body. In the ironing process, at least the inner surface of the enlarged portion in the range from the one end side of the raw pipe to the rear end position of the tapered portion along the pushing direction of the tapered portion is formed. Supported by a sleeve.

(3)上記(2)に記載の差厚管の製造方法において、前記しごき加工工程で、前記スリーブによって前記拡形部の内面を支える際の前記範囲が、前記後端位置より前記押し込み方向に沿って50mm以下の位置までであってもよい。 (3) In the method for manufacturing a differential thick tube according to (2) above, the range when the inner surface of the enlarged portion is supported by the sleeve in the ironing process is set in the pushing direction from the rear end position. It may be up to a position of 50 mm or less along the line.

(4)上記(1)〜(3)の何れか1項に記載の差厚管の製造方法において、前記しごき加工工程で、前記スリーブを、前記ダイスに係止させて位置固定してもよい。 (4) In the method for manufacturing a differential thickness tube according to any one of (1) to (3) above, the sleeve may be locked to the die to fix the position in the ironing process. ..

(5)上記(1)〜(4)の何れか1項に記載の差厚管の製造方法において、以下のようにしてもよい:前記素管及び前記差厚管が共に円管であり;前記素管の外径寸法をD1(mm)、前記拡形部の外径寸法をD2(mm)として、下記式1で示される拡径量EXが0.1%〜50%である。
拡管率(%)=(拡管後の外径−素管外径)/素管外径×100・・・(式1)
(5) In the method for producing a difference thickness tube according to any one of (1) to (4) above, the following may be performed: The raw tube and the difference thickness tube are both circular tubes; Assuming that the outer diameter of the raw pipe is D1 (mm) and the outer diameter of the enlarged portion is D2 (mm), the diameter expansion amount EX represented by the following formula 1 is 0.1% to 50%.
Tube expansion rate (%) = (outer diameter after tube expansion-elementary tube outer diameter) / element tube outer diameter x 100 ... (Equation 1)

(6)上記(5)に記載の差厚管の製造方法において、前記しごき加工工程後の、前記差厚管の減肉部における減肉率が10%〜90%の範囲内であってもよい。 (6) In the method for manufacturing a differential thickness pipe according to (5) above, even if the wall thinning rate in the thinned portion of the differential thickness pipe after the ironing process is within the range of 10% to 90%. Good.

(7)上記(1)〜(6)の何れか1項に記載の差厚管の製造方法において、前記素管としてシームレス鋼管を用いてもよい。 (7) In the method for manufacturing a differential thickness pipe according to any one of (1) to (6) above, a seamless steel pipe may be used as the raw pipe.

(8)本発明の一態様に係る差厚管の製造装置は、中空筒状の素管より差厚管を製造する装置であって、前記素管を収容するとともに前記素管の外形よりも大きな拡形凹部を含む収容部を有するダイスと;前記収容部内の前記素管の一端側に対して挿抜されるプラグ本体及びスリーブと;前記プラグ本体及び前記スリーブの挿抜を行う駆動機構と;前記スリーブを前記拡形凹部内に留める留置機構と;を備える。 (8) The device for manufacturing a differential thickness tube according to one aspect of the present invention is an device for manufacturing a differential thickness tube from a hollow tubular raw tube, and accommodates the raw tube and is larger than the outer shape of the raw tube. A die having an accommodating portion including a large enlarged recess; a plug body and a sleeve to be inserted and removed from one end side of the raw pipe in the accommodating portion; and a drive mechanism for inserting and removing the plug body and the sleeve; It is provided with an indwelling mechanism for fastening the sleeve in the enlarged recess.

(9)上記(8)に記載の差厚管の製造装置において、以下のようにしてもよい:前記プラグ本体が、前記プラグ本体の先端部よりも外形の小さい逃げ部を前記先端部よりも後端側の位置に有し;前記逃げ部を被覆可能に、前記スリーブが前記プラグ本体に対して外挿されている。 (9) In the thick tube manufacturing apparatus according to (8) above, the plug body may have a relief portion having a smaller outer shape than the tip portion of the plug body than the tip portion. It is located at the rear end side; the sleeve is extrapolated to the plug body so that the relief portion can be covered.

(10)上記(8)または(9)に記載の差厚管の製造装置において、以下のようにしてもよい:前記拡形凹部の、前記プラグ本体の押し込み方向に沿った先端側に、前記押し込み方向に向かって内形が先細りとなるテーパー凹部が形成され;前記留置機構が、少なくとも、前記素管の前記一端側より前記テーパー凹部の前記押し込み方向に沿った後端位置までを含む範囲に重なる位置に、前記スリーブを留置する。 (10) In the thick tube manufacturing apparatus according to (8) or (9) above, the following may be performed: The tip side of the enlarged concave portion along the pushing direction of the plug body. A tapered recess is formed in which the inner shape tapers toward the pushing direction; the indwelling mechanism covers at least one end of the raw pipe to the rear end position of the tapered recess along the pushing direction. The sleeves are placed at overlapping positions.

(11)上記(10)に記載の差厚管の製造装置において、前記素管の前記一端側から前記拡形凹部の前記後端位置までの間と、前記後端位置から前記プラグ本体の押し込み方向に沿った50mm以下の位置までの間とに重なる位置に、前記留置機構が前記スリーブを留置してもよい。 (11) In the differential pipe manufacturing apparatus according to (10) above, the plug body is pushed in between the one end side of the raw pipe and the rear end position of the enlarged recess and from the rear end position. The indwelling mechanism may indwell the sleeve at a position overlapping the position up to a position of 50 mm or less along the direction.

(12)上記(8)〜(11)の何れか1項に記載の差厚管の製造装置において、前記留置機構が、前記スリーブに設けられて前記ダイスに係止する係止部であってもよい。 (12) In the thick tube manufacturing apparatus according to any one of (8) to (11) above, the indwelling mechanism is a locking portion provided on the sleeve and locked to the die. May be good.

(13)上記(8)〜(11)の何れか1項に記載の差厚管の製造装置において、前記留置機構が、前記スリーブの挿抜停止位置を前記駆動機構に指示する制御部であってもよい。 (13) In the differential pipe manufacturing apparatus according to any one of (8) to (11) above, the indwelling mechanism is a control unit that instructs the drive mechanism to stop inserting and removing the sleeve. May be good.

(14)上記(8)〜(13)の何れか1項に記載の差厚管の製造装置において、前記プラグ本体の押し込み方向に垂直な断面で見た場合、前記収容部の形状が、円形、楕円形、矩形、線対称形状、のうちの何れかであり、前記プラグ本体の形状が、円形、楕円形、矩形、線対称形状、のうちの何れかであってもよい。 (14) In the device for manufacturing a differential thickness tube according to any one of (8) to (13) above, the shape of the accommodating portion is circular when viewed in a cross section perpendicular to the pushing direction of the plug body. , Elliptical, rectangular, or line-symmetrical, and the shape of the plug body may be any of circular, elliptical, rectangular, and line-symmetrical.

本発明の上記各態様によれば、幅広い加工条件に応じて柔軟に対応できる、差厚管の製造方法及び差厚管の製造装置を提供できる。 According to each of the above aspects of the present invention, it is possible to provide a method for manufacturing a differential thickness tube and an apparatus for manufacturing a differential thickness tube that can flexibly respond to a wide range of processing conditions.

本発明の一実施形態に係る差厚管の製造方法の各工程を、(a)〜(c)の順に説明する図であって、差厚管の製造装置をその軸線を含む断面で見た断面図である。It is a figure explaining each step of the manufacturing method of the differential thickness tube which concerns on one Embodiment of this invention in the order of (a)-(c), and the manufacturing apparatus of the differential thickness tube was seen in the cross section including the axis | line. It is a sectional view. 同製造方法で用いられるプラグを示す斜視図であって、(a)が係止工程時を示し、(b)がしごき加工工程時を示す。It is a perspective view which shows the plug used in the same manufacturing method, (a) shows the time of a locking process, and (b) shows the time of an ironing process. 同製造方法により製造された差厚管を示す図であって、その中心軸線を含む断面で見た場合の断面図である。It is a figure which shows the differential thickness tube manufactured by the same manufacturing method, and is the cross-sectional view when viewed in the cross section including the central axis. 同製造方法により製造された他の差厚管を示す図であって、その中心軸線を含む断面で見た場合の断面図である。It is a figure which shows the other thickness difference tube manufactured by the same manufacturing method, and is the cross-sectional view when viewed in the cross section including the central axis. 同製造方法を説明するために従来の製造方法と対比した部分拡大断面図であって、(a)が従来の製造方法を示し、(b)が本実施形態の製造方法を示す。In order to explain the manufacturing method, it is a partially enlarged cross-sectional view compared with the conventional manufacturing method, (a) shows the conventional manufacturing method, and (b) shows the manufacturing method of this embodiment. 従来の製造方法と本実施形態の製造方法とを対比する数値解析における各寸法規定を示す図であって、(a)が本実施形態の製造方法を示す断面図であり、(b)が従来の製造方法を示す断面図である。It is a figure which shows each dimension regulation in the numerical analysis which contrasts the manufacturing method of a conventional manufacturing method and the manufacturing method of this embodiment, (a) is a sectional view which shows the manufacturing method of this Embodiment, and (b) is a conventional It is sectional drawing which shows the manufacturing method of. 同数値解析の結果を示すグラフであり、(a)が従来の製造方法の場合を示し、(b)が本実施形態の製造方法の場合を示す。It is a graph which shows the result of the numerical analysis, (a) shows the case of the conventional manufacturing method, and (b) shows the case of the manufacturing method of this embodiment. 同数値解析の結果を示す他のグラフであり、(a)が従来の製造方法の場合を示し、(b)が本実施形態の製造方法の場合を示す。It is another graph which shows the result of the same numerical analysis, (a) shows the case of the conventional manufacturing method, and (b) shows the case of the manufacturing method of this embodiment. 同製造方法で用いられるプラグの変形例を示す斜視図であって、(a)が係止工程時を示し、(b)がしごき加工工程時を示す。It is a perspective view which shows the modification of the plug used in this manufacturing method, (a) shows the time of a locking process, and (b) shows the time of an ironing process. 同製造方法により製造される差厚管の他の例を示す図であって、(a)〜(e)は、中間部をその長手方向に直交する断面で見た断面図である。It is a figure which shows the other example of the thickness difference tube manufactured by the same manufacturing method, (a)-(e) is the cross-sectional view which looked at the intermediate part in the cross section orthogonal to the longitudinal direction.

本発明の一実施形態及びその変形例について、図面を参照しながら以下に説明を行う。
図1に示すように、本実施形態における差厚管の製造方法は、中空円筒形状の素管Wをダイス10内に配置し、素管Wの一端部Waに拡形部を形成した後、素管Wの一端部Waより他端部Wbに向かってプラグ20を押し込むことで絞り加工を行う。
以下に詳細を説明するが、素管Wの長手方向に沿った一端部Wbに向かう方向を先端側と呼び、素管Wの長手方向に沿った他端部Waに向かう方向を後端側と呼ぶ場合がある。
An embodiment of the present invention and a modification thereof will be described below with reference to the drawings.
As shown in FIG. 1, in the method for manufacturing a differential thickness tube in the present embodiment, a hollow cylindrical raw tube W is arranged in a die 10, an enlarged portion is formed at one end Wa of the raw tube W, and then an enlarged portion is formed. Drawing is performed by pushing the plug 20 from one end Wa of the raw tube W toward the other end Wb.
The details will be described below, but the direction toward one end Wb along the longitudinal direction of the raw pipe W is called the front end side, and the direction toward the other end Wa along the longitudinal direction of the raw pipe W is called the rear end side. May be called.

本実施形態における素管Wとしては、引張強度が290MPa以上のものが好適に用いられる。例えば、素管Wとして、引張強度が440MPa又は980MPaのものを用いることができる。また、素管Wの材質としては、鋼に加えて、アルミニウム等の他の金属素材にも適用できる。素管Wは、中空筒状の金属管(鋼管を含む)を例示することができ、特に丸形鋼管が好ましい。丸形鋼管としては、シームレス鋼管、UO管、スパイラル管、電縫鋼管の何れも適用可能である。 As the raw tube W in the present embodiment, one having a tensile strength of 290 MPa or more is preferably used. For example, as the raw tube W, a tube having a tensile strength of 440 MPa or 980 MPa can be used. Further, as the material of the raw pipe W, in addition to steel, it can be applied to other metal materials such as aluminum. As the raw pipe W, a hollow tubular metal pipe (including a steel pipe) can be exemplified, and a round steel pipe is particularly preferable. As the round steel pipe, any of seamless steel pipe, UO pipe, spiral pipe, and electrosewn steel pipe can be applied.

図1は、本実施形態に係る差厚管の製造方法の各工程を(a)〜(c)の順に説明する図であって、差厚管の製造装置をその軸線を含む断面で見た断面図である。図1中では、プラグ本体30のみ外形を示しており、その他は断面形状を示している。
まず、本実施形態に係る差厚管の製造装置について説明する。
本実施形態の差厚管の製造装置は、中空筒状の素管Wより差厚管Pを製造する装置である。図1(a)に示すように、差厚管の製造装置は、ダイス10と、プラグ20と、プラグ駆動部(駆動機構。不図示)と、制御部(不図示)と、を備える。
FIG. 1 is a diagram for explaining each step of the method for manufacturing a differential tube according to the present embodiment in the order of (a) to (c), and the device for manufacturing the differential tube is viewed in cross section including the axis thereof. It is a sectional view. In FIG. 1, only the plug main body 30 shows the outer shape, and the others show the cross-sectional shape.
First, an apparatus for manufacturing a differential thickness pipe according to the present embodiment will be described.
The device for manufacturing the difference thickness tube of the present embodiment is an device for manufacturing the difference thickness tube P from the hollow tubular raw tube W. As shown in FIG. 1A, the thickness difference tube manufacturing apparatus includes a die 10, a plug 20, a plug drive unit (drive mechanism, not shown), and a control unit (not shown).

ダイス10内には、素管Wの外径d1に対応する内径を有する中空小径部11aと、素管Wの外径d1よりも大きな内径を有する中空大径部11bと、中空小径部11aと中空大径部11bとの間に設けられたテーパー凹部11cとが形成されている。すなわち、ダイス10は、素管Wを収容するとともに素管Wの外形よりも大きな拡形凹部(中空大径部11b及びテーパー凹部11c)を含む収容部を有する。中空小径部11a、中空大径部11b及びテーパー凹部11cは、ダイス10内において同軸かつ互いに連通して配置されている。中空小径部11a、中空大径部11b及びテーパー凹部11cは、軸線CLに垂直な断面形状が円形である。
なお、上記の「素管Wの外径d1に対応する内径」とは、素管Wの外径d1に対し、中空小径部11a内外への素管Wの抜き差しが可能な程度の隙間寸法を加えた内径寸法を示す。
Inside the die 10, a hollow small diameter portion 11a having an inner diameter corresponding to the outer diameter d1 of the raw pipe W, a hollow large diameter portion 11b having an inner diameter larger than the outer diameter d1 of the raw pipe W, and a hollow small diameter portion 11a A tapered recess 11c provided between the hollow large diameter portion 11b and the hollow large diameter portion 11b is formed. That is, the die 10 has an accommodating portion for accommodating the raw pipe W and including an enlarged concave portion (hollow large diameter portion 11b and tapered concave portion 11c) larger than the outer shape of the raw pipe W. The hollow small diameter portion 11a, the hollow large diameter portion 11b, and the tapered recess 11c are arranged coaxially and in communication with each other in the die 10. The hollow small diameter portion 11a, the hollow large diameter portion 11b, and the tapered recess 11c have a circular cross-sectional shape perpendicular to the axis CL.
The above-mentioned "inner diameter corresponding to the outer diameter d1 of the raw pipe W" is a gap dimension that allows the raw pipe W to be inserted and removed inside and outside the hollow small diameter portion 11a with respect to the outer diameter d1 of the raw pipe W. The added inner diameter is shown.

図1及び図2に示すように、プラグ20は、プラグ本体30及びスリーブ40を有する。
プラグ本体30は、素管Wの内径d2よりも小さい外径の先端面31aを有するテーパー先端部31と、素管Wの内径d2よりも大きくてかつダイス10の中空小径部11aの内径よりも小さい外径を有する大径部32と、大径部32の外径よりも小さな外径を有する小径基端部33と、大径部32及び小径基端部33間に設けられたテーパー部34と、を備える。
As shown in FIGS. 1 and 2, the plug 20 has a plug body 30 and a sleeve 40.
The plug body 30 has a tapered tip portion 31 having a tip surface 31a having an outer diameter smaller than the inner diameter d2 of the raw pipe W, and an inner diameter larger than the inner diameter d2 of the raw pipe W and larger than the inner diameter of the hollow small diameter portion 11a of the die 10. A large diameter portion 32 having a small outer diameter, a small diameter base end portion 33 having an outer diameter smaller than the outer diameter of the large diameter portion 32, and a tapered portion 34 provided between the large diameter portion 32 and the small diameter base end portion 33. And.

図2に示すように、テーパー先端部31は、円形の先端面31aを先端とする円錐台形状をなしている。より具体的に言うと、図1(a)に示すように、テーパー先端部31は、プラグ本体30の軸線CLを含む断面で見た場合に、軸線CLに平行な線を基準としてテーパー角度θをなす外周面を有している。テーパー角度θは、1度〜40度の範囲内であることが好ましい。テーパー角度θが1度未満であると素管Wの一端部Waを必要十分に拡径させることができない。一方、テーパー角度θが40度超では、しごき加工時にプラグ本体30のテーパー先端部31に生じる局部面圧が過大となり、プラグ本体30の寿命低下を引き起こす可能性がある。 As shown in FIG. 2, the tapered tip portion 31 has a truncated cone shape with a circular tip surface 31a as the tip. More specifically, as shown in FIG. 1A, the taper tip portion 31 has a taper angle θ with respect to a line parallel to the axis CL when viewed in a cross section including the axis CL of the plug body 30. It has an outer peripheral surface that forms. The taper angle θ is preferably in the range of 1 degree to 40 degrees. If the taper angle θ is less than 1 degree, the diameter of one end Wa of the raw tube W cannot be expanded sufficiently. On the other hand, if the taper angle θ exceeds 40 degrees, the local surface pressure generated at the tapered tip portion 31 of the plug main body 30 during ironing processing becomes excessive, which may shorten the life of the plug main body 30.

図2に示すように、大径部32は、テーパー先端部31の後端に連なる円柱形状をなしている。より具体的に言うと、大径部32は、テーパー先端部31の後端と同じでかつ軸線CLに沿った各位置で一定の外径寸法を有している。
テーパー部34は、大径部32の後端に連なる円錐台形状をなしている。より具体的に言うと、テーパー部34は、大径部32の後端と同じでかつ軸線CLに沿って大径部32から離れるに従って縮径する円錐台形状をなしている。テーパー部34の先端側は、大径部32の外径寸法と同じ外径寸法を有している。
小径基端部33は、テーパー部34の後端に連なる円柱形状をなしている。より具体的に言うと、小径基端部33は、テーパー部34の後端と同じでかつ軸線CLに沿った各位置で一定の外径寸法を有している。小径基端部33の後端は、前記プラグ駆動部に接続されている。
As shown in FIG. 2, the large diameter portion 32 has a cylindrical shape connected to the rear end of the tapered tip portion 31. More specifically, the large diameter portion 32 has the same outer diameter as the rear end of the tapered tip portion 31 and has a constant outer diameter dimension at each position along the axis CL.
The tapered portion 34 has a truncated cone shape connected to the rear end of the large diameter portion 32. More specifically, the tapered portion 34 has a truncated cone shape which is the same as the rear end of the large diameter portion 32 and whose diameter is reduced as the distance from the large diameter portion 32 is along the axis CL. The tip side of the tapered portion 34 has the same outer diameter dimension as the outer diameter dimension of the large diameter portion 32.
The small-diameter base end portion 33 has a cylindrical shape connected to the rear end of the tapered portion 34. More specifically, the small-diameter base end portion 33 has the same outer diameter dimension as the rear end of the tapered portion 34 and has a constant outer diameter dimension at each position along the axis CL. The rear end of the small diameter base end portion 33 is connected to the plug drive portion.

プラグ本体30の外径寸法を軸線CLに沿って見た場合、前記先端面31aから始まってテーパー先端部31では徐々に拡径し、大径部32では一定外径を有し、テーパー部34では徐々に縮径し、そして小径基端部33では一定外径を有している。図1(a)に示すように、テーパー部34及び小径基端部33は大径部32よりも細くなっており、これらテーパー部34及び小径基端部33の周囲空間が逃げ部35となっている。逃げ部35は、大径部32の後端側に連なる環状の空間である。 When the outer diameter of the plug body 30 is viewed along the axis CL, the tapered tip 31 starts from the tip surface 31a and gradually expands, the large diameter 32 has a constant outer diameter, and the tapered portion 34. The diameter is gradually reduced, and the small diameter base end portion 33 has a constant outer diameter. As shown in FIG. 1A, the tapered portion 34 and the small diameter base end portion 33 are thinner than the large diameter portion 32, and the peripheral space of the tapered portion 34 and the small diameter base end portion 33 becomes the relief portion 35. ing. The relief portion 35 is an annular space connected to the rear end side of the large diameter portion 32.

図2に示すように、スリーブ40は筒状体である。スリーブ40は、テーパー部34の外周と小径基端部33の外周の一部とを覆うように、プラグ本体30に対して同軸に外挿されている。スリーブ40はプラグ本体30に対して固定されてないため、図2の(a)及び(b)に示すように、スリーブ40に対して同軸状態を保ったまま、プラグ本体30を相対移動させることができる。より具体的に言うと、図2(a)に示すように、プラグ本体30の逃げ部35をスリーブ40で覆うことと、図2(b)に示すように、小径基端部33の、テーパー部34から離間した部位をスリーブ40で覆うこととを行える。すなわち、スリーブ40は、逃げ部35を被覆可能なように、プラグ本体30に対して同軸配置されている。 As shown in FIG. 2, the sleeve 40 is a tubular body. The sleeve 40 is extrapolated coaxially with the plug body 30 so as to cover the outer circumference of the tapered portion 34 and a part of the outer circumference of the small diameter base end portion 33. Since the sleeve 40 is not fixed to the plug body 30, the plug body 30 is relatively moved while maintaining the coaxial state with respect to the sleeve 40, as shown in FIGS. 2A and 2B. Can be done. More specifically, as shown in FIG. 2A, the relief portion 35 of the plug body 30 is covered with the sleeve 40, and as shown in FIG. 2B, the taper of the small diameter base end portion 33. The portion separated from the portion 34 can be covered with the sleeve 40. That is, the sleeve 40 is coaxially arranged with respect to the plug body 30 so that the relief portion 35 can be covered.

図2(b)に示すように、スリーブ40の先端には、テーパー部34のテーパー形状に合致するよう、テーパー面41が形成されている。よって、スリーブ40内には、その先端から後方に向かって縮径するテーパー面41と、このテーパー面41に連なってかつ軸方向各位置での内径寸法が一定である円形の内周面42とが形成されている。
スリーブ40の形状寸法としては、例えば自動車用部品への適用を想定した場合、外径として10〜200mmφ、より好ましくは50〜100mmφを例示することができる。また、スリーブ40の肉厚としては、その外径の3〜50%を例示することができる。なお、本実施形態のスリーブ40では、後述する図6(a)に示す符号gに示す隙間寸法が0mmになっている。すなわち、しごき加工工程中は、素管Wの一端部Wa側の内周面に対してスリーブ40の外周面が合致する。
As shown in FIG. 2B, a tapered surface 41 is formed at the tip of the sleeve 40 so as to match the tapered shape of the tapered portion 34. Therefore, in the sleeve 40, there is a tapered surface 41 whose diameter is reduced from the tip to the rear, and a circular inner peripheral surface 42 which is connected to the tapered surface 41 and whose inner diameter dimension is constant at each position in the axial direction. Is formed.
As the shape and dimensions of the sleeve 40, for example, assuming application to automobile parts, an outer diameter of 10 to 200 mmφ, more preferably 50 to 100 mmφ can be exemplified. Further, as the wall thickness of the sleeve 40, 3 to 50% of the outer diameter thereof can be exemplified. In the sleeve 40 of the present embodiment, the gap dimension indicated by the reference numeral g shown in FIG. 6A, which will be described later, is 0 mm. That is, during the ironing process, the outer peripheral surface of the sleeve 40 matches the inner peripheral surface on the Wa side of one end of the raw pipe W.

本実施形態は、以上説明のプラグ20の構成と、このプラグ20の用い方とが、特に特徴的となっている。この特徴を説明するために、先ず、本実施形態における差厚管の製造装置による製造方法を以下に説明する。 In this embodiment, the configuration of the plug 20 described above and the usage of the plug 20 are particularly characteristic. In order to explain this feature, first, the manufacturing method by the differential pipe manufacturing apparatus in the present embodiment will be described below.

本実施形態に係る製造方法で差厚管を製造するには、まず、図1(a)に示すように、ダイス10の内部に素管Wを同軸に挿入する。このとき、ダイス10の中空大径部11b内に素管Wの一端部Waが位置するように位置決めする。そして、ダイス10と素管Wはそれぞれ固定させた状態とする。すなわち、ダイス10においては、図示されない基台に固定された状態となっている。また、素管Wにおいては、素管Wの他端部Wbが紙面左側へ奥深く進まないようにせき止められており、これにより、ダイス10に対する素管Wの長手方向の相対位置が固定されている。 In order to manufacture the differential thickness tube by the manufacturing method according to the present embodiment, first, as shown in FIG. 1A, the raw tube W is coaxially inserted inside the die 10. At this time, the position is set so that one end Wa of the raw pipe W is located in the hollow large diameter portion 11b of the die 10. Then, the die 10 and the raw tube W are in a fixed state. That is, the die 10 is in a state of being fixed to a base (not shown). Further, in the raw pipe W, the other end Wb of the raw pipe W is dammed so as not to advance deeply to the left side of the paper surface, whereby the relative position of the raw pipe W with respect to the die 10 in the longitudinal direction is fixed. ..

そして、図1(b)に示す係止工程として、ダイス10及び素管Wを固定させた状態のまま、素管Wの一端部Wa側から素管Wの内部に向かってプラグ20を押し込んでいく。その際、図1(b)及び図2(a)に示すように、プラグ本体30の逃げ部35をスリーブ40で覆ったまま、プラグ20を前記プラグ駆動部により押し込んでいく。すなわち、プラグ本体30の大径部32の外周面にスリーブ40の外周面が連なった状態で、前記プラグ駆動部により、プラグ本体30及びスリーブ40の双方に、軸線CLに沿った軸力を付与する。その結果、プラグ本体30及びスリーブ40が一体になって素管Wの一端部Waに押し込まれていく。 Then, as the locking step shown in FIG. 1B, the plug 20 is pushed from one end Wa side of the raw pipe W toward the inside of the raw pipe W while the die 10 and the raw pipe W are fixed. I will go. At that time, as shown in FIGS. 1 (b) and 2 (a), the plug 20 is pushed by the plug drive unit while the relief portion 35 of the plug main body 30 is covered with the sleeve 40. That is, in a state where the outer peripheral surface of the sleeve 40 is connected to the outer peripheral surface of the large diameter portion 32 of the plug main body 30, the plug driving unit applies an axial force along the axis CL to both the plug main body 30 and the sleeve 40. To do. As a result, the plug body 30 and the sleeve 40 are integrally pushed into one end Wa of the raw pipe W.

そして、テーパー先端部31がダイス10のテーパー凹部11cの位置に到達するまで押し込む。このようにしてテーパー先端部31がダイス10のテーパー凹部11cの位置に到達するまでの間、素管Wはダイス10に対する相対位置が固定され続けているので、素管Wがテーパー先端部31によってダイス10から押し出されてしまうことがない。また、スリーブ40もプラグ本体30と共に押し込まれていき、その先端部であるテーパー面41が中空大径部11b内の位置に到達する。
テーパー先端部31がテーパー凹部11cの位置に到達したか否かは、例えば、プラグ本体30の押し込みストローク量、または、プラグ本体30の押し込みに伴って増加する反力を測定し、この測定値を前記制御部で判断することにより管理できる。
Then, the taper tip portion 31 is pushed in until it reaches the position of the taper recess 11c of the die 10. In this way, until the tapered tip portion 31 reaches the position of the tapered recess 11c of the die 10, the position of the raw tube W with respect to the die 10 continues to be fixed, so that the raw tube W is formed by the tapered tip portion 31. It will not be pushed out from the die 10. Further, the sleeve 40 is also pushed in together with the plug body 30, and the tapered surface 41 at the tip thereof reaches a position in the hollow large diameter portion 11b.
Whether or not the tapered tip portion 31 has reached the position of the tapered recess 11c is determined by measuring, for example, the pushing stroke amount of the plug main body 30 or the reaction force increasing with the pushing of the plug main body 30, and measuring this measured value. It can be managed by making a judgment by the control unit.

図1(a)の時点では、ダイス10の内部に素管Wを配置した際、素管Wの一端部Waがダイス10の中空大径部11b内に位置しているため、ダイス10の中空大径部11bと素管Wの一端部Waとの間に隙間sが生じている。この状態から図1(b)に示すようにプラグ20を押し込むと、素管Wの一端部Waがプラグ本体30のテーパー先端部31及び大径部32によって拡径される。これにより、隙間sが徐々に小さくなり、ついには一端部Wa側の外周面がダイス10のテーパー凹部11cの内周面及び中空大径部11bの内周面に合致する。このようにして素管Wの一端部Waに、直管形状の拡形部1cと、この拡形部1cに連なる係止部1e1とが形成される。係止部1e1は、後述する中間部1eの一部をなし、ダイス10のテーパー凹部11cに密接するテーパー面を外周面とする円錐台形状を有している。 At the time of FIG. 1A, when the raw tube W is arranged inside the die 10, one end Wa of the raw tube W is located in the hollow large diameter portion 11b of the die 10, so that the hollow of the die 10 is hollow. A gap s is formed between the large diameter portion 11b and one end portion Wa of the raw pipe W. When the plug 20 is pushed in from this state as shown in FIG. 1 (b), the diameter of one end Wa of the raw tube W is expanded by the tapered tip 31 and the large diameter 32 of the plug body 30. As a result, the gap s gradually becomes smaller, and finally, the outer peripheral surface on the Wa side of one end portion matches the inner peripheral surface of the tapered recess 11c of the die 10 and the inner peripheral surface of the hollow large diameter portion 11b. In this way, a straight tube-shaped enlarged portion 1c and a locking portion 1e1 connected to the expanded portion 1c are formed at one end Wa of the raw pipe W. The locking portion 1e1 forms a part of the intermediate portion 1e described later, and has a truncated cone shape having a tapered surface in close contact with the tapered recess 11c of the die 10 as an outer peripheral surface.

このようにして形成された拡形部1cの拡径量をExとした場合、以下の規定を満たすことが好ましい。すなわち、本実施形態の素管W及び差厚管Pは共に円管であるため、素管Wの外径寸法をD1(mm)、拡径部(拡形部)1cの外径寸法をD2(mm)として、下記式1で示される拡径量EXが、0.1%〜50%であることが好ましい。すなわち、拡径量Exが0.1%未満であると、必要最低限な係止が得られず、素管Wの滑りを生じる虞がある。また、拡径量Exが50%を超えると、拡管部1cに割れが発生する不具合を生じる虞がある。 When the diameter expansion amount of the enlarged portion 1c formed in this way is Ex, it is preferable that the following regulations are satisfied. That is, since both the raw pipe W and the differential thickness pipe P of the present embodiment are circular pipes, the outer diameter of the raw pipe W is D1 (mm) and the outer diameter of the enlarged diameter portion (expanded portion) 1c is D2. As (mm), the diameter expansion amount EX represented by the following formula 1 is preferably 0.1% to 50%. That is, if the diameter expansion amount Ex is less than 0.1%, the minimum necessary locking cannot be obtained, and the raw pipe W may slip. Further, if the diameter expansion amount Ex exceeds 50%, there is a possibility that the tube expansion portion 1c may be cracked.

Ex(%)=(D2−D1)/D1×100・・・(式1) Ex (%) = (D2-D1) / D1 × 100 ... (Equation 1)

次に、しごき加工工程として、ダイス10の固定は維持する一方、素管Wの固定は解除させた状態で、プラグ本体30を素管Wの他端部Wb側に向けて更に押し込む。すなわち、拡形部1cが形成された後は、素管Wの他端部Wbへのせき止めを解除する。その後、プラグ20を更に押し込む。プラグ20を更に押し込むことで、素管Wが一端部Waから他端部Wb側に向けて押されるが、前記係止工程において素管Wに形成された前記係止部1e1が、ダイス10のテーパー凹部11cに係止されたままとなるので、素管Wは動かない。 Next, as a squeezing process, the plug body 30 is further pushed toward the other end Wb side of the raw pipe W while the fixing of the die 10 is maintained and the fixing of the raw pipe W is released. That is, after the expanded portion 1c is formed, the damming to the other end portion Wb of the raw pipe W is released. After that, the plug 20 is pushed further. By further pushing the plug 20, the raw tube W is pushed from one end Wa toward the other end Wb, and the locking portion 1e1 formed on the raw tube W in the locking step is the die 10. Since it remains locked in the tapered recess 11c, the raw tube W does not move.

プラグ20を押し込むことで、プラグ本体30の大径部32が素管Wの他端部Wb側に向かって押し込まれる。プラグ本体30の大径部32が押し込まれた素管Wの中間部1eでは、元々の素管Wの内径d2がプラグ本体30の大径部32の外径に対応する大きさに拡径される。その一方で、素管Wの中間部1eはダイス10の中空小径部11a内に位置して周囲より外径寸法が規制されているため、中間部1eの外径d1は拡径されない。従って、素管Wの中間部1eは、素管Wの元々の外径d1が維持されたまま内径d2が拡径されて減肉する、しごき加工を受ける。 By pushing the plug 20, the large diameter portion 32 of the plug main body 30 is pushed toward the other end Wb side of the raw pipe W. In the intermediate portion 1e of the raw pipe W into which the large diameter portion 32 of the plug main body 30 is pushed, the inner diameter d2 of the original raw pipe W is expanded to a size corresponding to the outer diameter of the large diameter portion 32 of the plug main body 30. To. On the other hand, since the intermediate portion 1e of the raw pipe W is located in the hollow small diameter portion 11a of the die 10 and the outer diameter dimension is regulated from the surroundings, the outer diameter d1 of the intermediate portion 1e is not expanded. Therefore, the intermediate portion 1e of the raw pipe W is subjected to ironing processing in which the inner diameter d2 is expanded and the wall thickness is reduced while the original outer diameter d1 of the raw pipe W is maintained.

なお、しごき加工開始の直前に素管Wのせき止めを解除する理由は、しごき加工に伴う素管Wの肉の流れを阻害しないことにある。すなわち、しごき加工によって素管Wの中間部1eが減肉される際、その減肉分の肉の行き先を確保するために、素管Wのせき止めを解除している。これにより、素管Wの紙面左側の部分が座屈することを防いでいる。本実施形態では、しごき加工による素管Wの減肉分が紙面左側に流れるため、素管Wの全長はしごき加工前よりも若干長くなる。 The reason for releasing the damming of the raw pipe W immediately before the start of the ironing process is that the flow of the meat of the raw tube W due to the ironing process is not obstructed. That is, when the intermediate portion 1e of the raw pipe W is thinned by the ironing process, the damming of the raw pipe W is released in order to secure the destination of the meat for the thinned portion. This prevents the left side portion of the paper surface of the raw tube W from buckling. In the present embodiment, since the thinning portion of the raw pipe W due to the ironing process flows to the left side of the paper surface, the total length of the raw tube W is slightly longer than that before the ironing process.

プラグ20の押し込みをさらに進めていくことで、しごき加工の範囲が広がっていく。しかし、このままプラグ20を押し込んでいくと、しごき加工の進展に伴って素管Wの内周面とプラグ20の外周面との接触面積が徐々に増えていくため、プラグ20を押し出す際と引き抜く際との双方において、大きな加工力が必要とされる。 By further pushing the plug 20, the range of ironing will be expanded. However, if the plug 20 is pushed in as it is, the contact area between the inner peripheral surface of the raw tube W and the outer peripheral surface of the plug 20 gradually increases as the ironing process progresses, so that the plug 20 is pulled out when it is pushed out. A large processing force is required in both cases.

これを避けるため、本実施形態では、図1(c)に示すように軸線CLに沿って見た場合に、スリーブ40の先端位置がテーパー凹部11cの先端位置(縮径の終端位置)から所定距離を超えた時点で、スリーブ40の押し込みを止めて固定する。そして、スリーブ40の軸線CLに沿った位置がテーパー凹部11cと重なるように位置固定して留置したまま、プラグ本体30の押し込みを継続して行う。この動作は、前記制御部が前記プラグ駆動部に指示することで行われる。すなわち、本実施形態の差厚管の製造装置では、前記制御部が、スリーブ40をテーパー凹部11c及び中空大径部11b(拡形凹部)内に留めるために、スリーブ40の挿抜停止位置を指示する留置機構として機能する。 In order to avoid this, in the present embodiment, when viewed along the axis CL as shown in FIG. 1 (c), the tip position of the sleeve 40 is predetermined from the tip position (end position of reduced diameter) of the tapered recess 11c. When the distance is exceeded, the sleeve 40 is stopped and fixed. Then, the plug body 30 is continuously pushed in while the position of the sleeve 40 along the axis CL is fixed so as to overlap the tapered recess 11c and is indwelled. This operation is performed when the control unit instructs the plug drive unit. That is, in the differential pipe manufacturing apparatus of the present embodiment, the control unit instructs the insertion / removal stop position of the sleeve 40 in order to keep the sleeve 40 in the tapered recess 11c and the hollow large diameter portion 11b (expanded recess). Functions as an indwelling mechanism.

さらにプラグ本体30の押し込みを進めても、素管Wの内周面に接触するのはテーパー先端部31及び大径部32だけであり、前記逃げ部35が有るために小径基端部33は接触しない。よって、プラグ本体30の押し込みを進めていっても前記接触面積は増えないため、加工力を増すことなく、しごき加工を進めることができる。しかも、拡形部1cはその内周面がスリーブ40の外周面によって支えられているため、縮径が禁止されている。そのため、テーパー凹部11cに対する拡形部1cの係止状態が維持されるので、プラグ本体30の押し込みにより素管Wに加わる軸力を受け止め続けることができる。その結果、ダイス10内における素管Wの滑りを生じることなく、図1(c)に示すように差厚管Pを得ることができる。 Even if the plug body 30 is pushed in further, only the tapered tip portion 31 and the large diameter portion 32 come into contact with the inner peripheral surface of the raw pipe W, and the small diameter base end portion 33 has the relief portion 35. Do not touch. Therefore, even if the plug body 30 is pushed in, the contact area does not increase, so that the ironing process can be performed without increasing the processing force. Moreover, since the inner peripheral surface of the enlarged portion 1c is supported by the outer peripheral surface of the sleeve 40, the diameter reduction is prohibited. Therefore, since the locked state of the enlarged portion 1c with respect to the tapered concave portion 11c is maintained, it is possible to continue to receive the axial force applied to the raw pipe W by pushing the plug main body 30. As a result, the differential thickness tube P can be obtained as shown in FIG. 1 (c) without causing the raw tube W to slip in the die 10.

なお、しごき加工による中間部1eの強度の向上効果を得るためには、しごき加工による素管Wの減肉率が10%以上である必要がある。一方、しごき加工による素管Wの減肉率が90%を超えると、破断や焼き付き等が生じる恐れがある。したがって、しごき加工による素管Wの減肉率は10〜90%の範囲内がよい。好ましくは減肉率を20〜80%の範囲内とするのがよい。なお、減肉率(%)は、素管Wのしごき加工前の肉厚をd0とし、しごき加工後における中間部1eの肉厚をdとした時に、(d0−d)/d0×100(%)で表される。 In order to obtain the effect of improving the strength of the intermediate portion 1e by the ironing process, the wall thinning rate of the raw tube W by the ironing process needs to be 10% or more. On the other hand, if the wall thinning rate of the raw tube W by ironing exceeds 90%, breakage or seizure may occur. Therefore, the thinning rate of the raw tube W by ironing is preferably in the range of 10 to 90%. The wall thinning rate is preferably in the range of 20 to 80%. The wall thinning rate (%) is (d0−d) / d0 × 100 (d0−d) / d0 × 100 when the wall thickness of the raw pipe W before ironing is d0 and the wall thickness of the intermediate portion 1e after ironing is d. %).

ここで、中間部1eでしごき加工された部分の肉厚dが、素管Wの長手方向に沿って見て一様でなく分布がある場合には、最も減肉量が多い箇所で求めた数値を減肉率として採用する。すなわち、しごき加工された部分の中で、その長手方向に沿って見た場合にd0からdを差し引いた差分(相当歪み量)が最も大きい箇所で求めた値を、上述の減肉率として採用する。さらに言うと、しごき加工された部分の周方向に沿って減肉量が一様でなく分布がある場合には、その周方向分布の中で最も減肉量が多い箇所で求めた値を、上述の減肉率として採用する。
なお、減肉率は、プラグ本体30の大径部32の外径とスリーブ40の外径とを変化させることによって調整可能である。
Here, when the wall thickness d of the portion ironed in the intermediate portion 1e is not uniform and distributed along the longitudinal direction of the raw pipe W, it is determined at the portion having the largest amount of wall loss. Use the value as the wall thinning rate. That is, among the ironed parts, the value obtained at the place where the difference (equivalent strain amount) obtained by subtracting d from d0 when viewed along the longitudinal direction is the largest is adopted as the above-mentioned wall thinning rate. To do. Furthermore, if the amount of wall loss is not uniform and distributed along the circumferential direction of the ironed part, the value obtained at the part with the largest amount of wall loss in the circumferential distribution is calculated. It is adopted as the above-mentioned wall thinning rate.
The wall thinning rate can be adjusted by changing the outer diameter of the large diameter portion 32 of the plug body 30 and the outer diameter of the sleeve 40.

図1(c)に示す例では、プラグ本体30のテーパー先端部31及び大径部32が、素管Wの他端部Wbの手前の位置まで押し込まれる。この図1(c)に示される位置でプラグ本体30の押し込みを停止させると、素管Wの中間部1eよりも他端部Wb側の部分は未加工ままとなる。なお、本明細書で言う「未加工まま」の部分とは、差厚管Pにおいて、母材である加工前の素管Wのものと殆ど同じ強度(引張強度)または硬度を有する部分を言う。 In the example shown in FIG. 1C, the tapered tip portion 31 and the large diameter portion 32 of the plug body 30 are pushed to a position in front of the other end portion Wb of the raw pipe W. When the pushing of the plug main body 30 is stopped at the position shown in FIG. 1 (c), the portion of the raw tube W on the other end Wb side of the intermediate portion 1e remains unprocessed. The “unprocessed” portion referred to in the present specification refers to a portion of the differential thickness tube P having almost the same strength (tensile strength) or hardness as that of the unprocessed raw tube W which is the base material. ..

以上説明のように、本実施形態の差厚管の製造方法は、素管Wをダイス10内に配置し、素管Wの長手方向への移動を規制した状態で、素管Wの一端部Wa側よりプラグ本体30をスリーブ40と共に押し込み、一端部Wa側の外形(外径)を拡大させた拡形部(拡径部)1cを形成し、拡形部1cをダイス10に係止させる係止工程と;素管Wの前記規制を解く一方で素管Wの前記係止は維持してかつ、拡形部1cの内面を、スリーブ40で支えた状態で、プラグ本体30をさらに素管Wの他端側に向かって押し込み、素管Wの外形(外径)を維持したまま内形(内径)を拡げるしごき加工を行う、しごき加工工程と;を有する。そして、この、差厚管の製造方法によれば、中空筒状の素管Wより差厚管Pを製造することができる。 As described above, in the method for manufacturing the differential thick pipe of the present embodiment, one end of the raw pipe W is provided in a state where the raw pipe W is arranged in the die 10 and the movement of the raw pipe W in the longitudinal direction is restricted. The plug body 30 is pushed together with the sleeve 40 from the Wa side to form an enlarged portion (diameter expanded portion) 1c in which the outer diameter (outer diameter) of one end Wa side is enlarged, and the enlarged portion 1c is locked to the die 10. Locking step; While releasing the regulation of the raw tube W, the locking of the raw tube W is maintained, and the inner surface of the enlarged portion 1c is supported by the sleeve 40, and the plug main body 30 is further connected. It has a squeezing process in which the inner shape (inner diameter) is expanded while maintaining the outer diameter (outer diameter) of the raw pipe W by pushing toward the other end side of the pipe W. Then, according to this method of manufacturing the difference thickness tube, the difference thickness tube P can be manufactured from the hollow tubular raw tube W.

図3に、図1(a)〜図1(c)に示す工程を経て製造された差厚管Pの断面模式図を示す。なお、以下の説明において、製造後の差厚管Pを加工前及び加工中の素管Wと区別して説明するために、各部に対して新たな符号を割り当てる。また、素管Wの各部との対応関係を明記するために、一部、括弧付きで、素管Wの時点における各部の符合を併記する。 FIG. 3 shows a schematic cross-sectional view of the differential thickness tube P manufactured through the steps shown in FIGS. 1 (a) to 1 (c). In the following description, in order to distinguish the difference thickness tube P after production from the raw tube W before and during processing, a new reference numeral is assigned to each part. In addition, in order to clarify the correspondence with each part of the raw pipe W, the code of each part at the time of the raw pipe W is also shown in parentheses.

図3に示す差厚管Pは、一端部101a(Wa)側にあって素管Wから拡径された拡径部101c(1c)と、一端部101aと他端部101d(Wb)との間にあってしごき加工を受けた中間部101e(1e)と、中間部101eよりも他端部101d側にあって素管Wのまま加工を受けていない未加工部101fとから構成される。中間部101eは、拡径部101c及び未加工部101fとのそれぞれの境界において、ダイス10のテーパー凹部11c及びプラグ本体30のテーパー先端部31によって加工を受けた部分も含んでいる。すなわち、中間部101eは、一端部101aから他端部101dに向かって見た場合に、内径が一定で外径が先細りとなる係止部101e1(1e1)と、内径及び外径とも一定の直管部101e2と、外径が一定で内径が先細りとなるテーパー部101e3と、を含んでいる。そして、拡径部101cの硬度の平均値をH1、未加工部101fの硬度の平均値をH3、係止部101e1の硬度の平均値をH4、直管部101e2の硬度の平均値をH5、テーパー部101e3の硬度の平均値をH6とした場合に、H5>H6≧H3及びH5>H4>H1の両式を満たす。 The difference thickness pipe P shown in FIG. 3 has a diameter-expanded portion 101c (1c) on the one end portion 101a (Wa) side and expanded in diameter from the raw pipe W, and one end portion 101a and the other end portion 101d (Wb). It is composed of an intermediate portion 101e (1e) that has been ironed in between, and an unprocessed portion 101f that is on the other end 101d side of the intermediate portion 101e and has not been processed as the raw pipe W. The intermediate portion 101e also includes a portion processed by the tapered concave portion 11c of the die 10 and the tapered tip portion 31 of the plug body 30 at each boundary between the enlarged diameter portion 101c and the unprocessed portion 101f. That is, the intermediate portion 101e has a straight locking portion 101e1 (1e1) having a constant inner diameter and a tapered outer diameter when viewed from one end 101a to the other end 101d, and a straight portion having a constant inner diameter and outer diameter. It includes a pipe portion 101e2 and a tapered portion 101e3 having a constant outer diameter and a tapered inner diameter. The average hardness of the enlarged diameter portion 101c is H1, the average hardness of the unprocessed portion 101f is H3, the average hardness of the locking portion 101e1 is H4, and the average hardness of the straight pipe portion 101e2 is H5. When the average value of the hardness of the tapered portion 101e3 is H6, both the equations of H5> H6 ≧ H3 and H5> H4> H1 are satisfied.

差厚管Pの中空部101bは、拡径部101cと中間部101eとにおいて元の素管Wの内径d2よりも拡径され、未加工部101fでは元の素管Wの内径d2のままとなっている。また、差厚管Pの外径は、係止部101e1において素管Wの外径d1から徐々に拡径され、そして拡径部101cにおいては素管Wの外径d1よりも拡径されたまま一定となっている。一方、中間部101eのうちで係止部101e1を除く部分と、未加工部101fは、素管Wの外径d1と等しい外径のままとなっている。これにより、拡径部101c及び未加工部101fにおける肉厚が比較的厚く、中間部101eにおける肉厚が比較的薄い、差厚管Pとなっている。 The hollow portion 101b of the differential thickness pipe P has a larger diameter than the inner diameter d2 of the original raw pipe W in the enlarged diameter portion 101c and the intermediate portion 101e, and the inner diameter d2 of the original raw pipe W remains in the unprocessed portion 101f. It has become. Further, the outer diameter of the differential thickness pipe P is gradually increased from the outer diameter d1 of the raw pipe W in the locking portion 101e1, and is larger than the outer diameter d1 of the raw pipe W in the enlarged diameter portion 101c. It remains constant. On the other hand, the portion of the intermediate portion 101e excluding the locking portion 101e1 and the unprocessed portion 101f have an outer diameter equal to the outer diameter d1 of the raw pipe W. As a result, the wall thickness of the enlarged diameter portion 101c and the unprocessed portion 101f is relatively thick, and the wall thickness of the intermediate portion 101e is relatively thin.

図3に示す差厚管Pにおいては、拡径部101c及び未加工部101fに対する加工量が小さいので、この部分では加工硬化が生じていないか、生じていたとしても極僅かである。従って、拡径部101c及び未加工部101fの強度が比較的低く、これらの部分に対して曲げ加工等の後加工を行う場合であっても、加工硬化を緩和するための焼鈍処理等が不要になる。 In the differential thickness tube P shown in FIG. 3, since the amount of work with respect to the enlarged diameter portion 101c and the unprocessed portion 101f is small, work hardening does not occur in this portion, or even if it does occur, it is very small. Therefore, the strength of the enlarged diameter portion 101c and the unprocessed portion 101f is relatively low, and even when post-processing such as bending is performed on these portions, annealing treatment or the like for alleviating work hardening is unnecessary. become.

また、差厚管Pの中間部101eに対する加工量が大きいので、中間部101eは加工硬化によって強度が比較的高くなっている。すなわち、差厚管Pの長手方向に沿った硬度分布(ビッカース硬度分布。なお、ビッカース硬度分布の代わりに、引張強度分布によっても判断可能)を見た場合、未加工部101fの硬度が最も低く、拡径部101cの硬度が未加工部101fの硬度よりも若干高く、そして、中間部101eの硬度が拡径部101cの硬度よりも高くなっている。したがって、中間部101eが最も高い硬度を有するため、高い機械強度を求められる部位として好適である。また、相対的に低い硬度を有する未加工部101fと拡径部101cは、曲げ加工などの後加工を求められる部位として好適である。 Further, since the amount of processing of the differential thickness tube P with respect to the intermediate portion 101e is large, the strength of the intermediate portion 101e is relatively high due to work hardening. That is, when looking at the hardness distribution along the longitudinal direction of the differential thickness tube P (Vickers hardness distribution, which can be determined by the tensile strength distribution instead of the Vickers hardness distribution), the hardness of the unprocessed portion 101f is the lowest. The hardness of the enlarged diameter portion 101c is slightly higher than the hardness of the unprocessed portion 101f, and the hardness of the intermediate portion 101e is higher than the hardness of the enlarged diameter portion 101c. Therefore, since the intermediate portion 101e has the highest hardness, it is suitable as a portion where high mechanical strength is required. Further, the unprocessed portion 101f and the enlarged diameter portion 101c, which have relatively low hardness, are suitable as portions where post-processing such as bending processing is required.

また、中間部101eの内面は、しごき加工を受けたことにより表面粗度が小さくなっている。表面粗度が小さくなると疲労特性が高まるので、中間部101eは、加工硬化による強度向上に加えて、内面の表面粗度を小さくしたことによる疲労特性向上も得られる。したがって、軽量でありながら高い強度を実現している。このような相乗効果は、単なる切削加工による薄肉化では得られない。 Further, the inner surface of the intermediate portion 101e has a reduced surface roughness due to the ironing process. Since the fatigue characteristics increase as the surface roughness decreases, in addition to the strength improvement due to work hardening, the fatigue characteristics of the intermediate portion 101e can also be improved by reducing the surface roughness of the inner surface. Therefore, it is lightweight yet has high strength. Such a synergistic effect cannot be obtained by simply thinning the wall by cutting.

また、図4には、図1(a)〜図1(c)に示された工程を経て製造された差厚管Pの別の例を示す。図4に示す差厚管Pは、図1(c)に示したしごき加工工程において、プラグ本体30の大径部32が素管Wの他端部Wbに至るまでプラグ本体30を押し込むことによって製造された差厚管である。 Further, FIG. 4 shows another example of the differential thickness tube P manufactured through the steps shown in FIGS. 1 (a) to 1 (c). The differential thickness tube P shown in FIG. 4 is formed by pushing the plug body 30 until the large diameter portion 32 of the plug body 30 reaches the other end Wb of the raw tube W in the ironing process shown in FIG. 1 (c). It is a manufactured differential thickness pipe.

図4に示す差厚管Pは、一端部111a(Wa)側にあって素管Wから拡径された拡径部111c(1c)と、一端部111aと他端部111d(Wb)との間にあってしごき加工を受けた中間部111e(1e)と、中間部111eよりも他端部111d側にあって中間部111eと同様にしごき加工を受けた他端部分111fとから構成される。中間部111eは、拡径部111cとの境界において、ダイス10のテーパー凹部11c及びプラグ本体30のテーパー先端部31によって加工を受けた部分も含んでいる。すなわち、中間部111eは、係止部111e1(1e1)を含んでいる。係止部111e1は、前記係止部101e1と同じ形状を有するので、ここではその重複説明を省略する。 The differential thickness pipe P shown in FIG. 4 has a diameter-expanded portion 111c (1c) on the one end portion 111a (Wa) side and expanded in diameter from the raw pipe W, and one end portion 111a and the other end portion 111d (Wb). It is composed of an intermediate portion 111e (1e) that has been ironed in between and an other end portion 111f that is on the other end 111d side of the intermediate portion 111e and has been ironed in the same manner as the intermediate portion 111e. The intermediate portion 111e also includes a portion processed by the tapered recess 11c of the die 10 and the tapered tip portion 31 of the plug body 30 at the boundary with the enlarged diameter portion 111c. That is, the intermediate portion 111e includes the locking portion 111e1 (1e1). Since the locking portion 111e1 has the same shape as the locking portion 101e1, the overlapping description thereof will be omitted here.

差厚鋼管111の中空部111bは、その長手方向の全部の内径が素管Wの内径d2よりも拡径されている。また、差厚鋼管111の外径は、係止部111e1において素管Wの外径d1から徐々に拡径され、そして拡径部111cにおいては素管Wの外径d1よりも拡径されたまま一定となっている。一方、中間部111eのうちで係止部111e1を除く部分と、他端部分111fとは、素管Wの外径d1と等しい外径のままとなっている。これにより、係止部111e1及び拡径部111cにおける肉厚が比較的厚く、中間部111eのうちの係止部111e1を除いた部分と、他端部分111fとにおける肉厚が比較的薄い差厚管Pとなっている。 The entire inner diameter of the hollow portion 111b of the differential thickness steel pipe 111 in the longitudinal direction is larger than the inner diameter d2 of the raw pipe W. Further, the outer diameter of the differential thickness steel pipe 111 was gradually increased from the outer diameter d1 of the raw pipe W in the locking portion 111e1 and larger than the outer diameter d1 of the raw pipe W in the enlarged diameter portion 111c. It remains constant. On the other hand, the portion of the intermediate portion 111e excluding the locking portion 111e1 and the other end portion 111f have an outer diameter equal to the outer diameter d1 of the raw pipe W. As a result, the wall thickness of the locking portion 111e1 and the enlarged diameter portion 111c is relatively thick, and the thickness difference between the portion of the intermediate portion 111e excluding the locking portion 111e1 and the other end portion 111f is relatively thin. It is a tube P.

図4に示す差厚管Pにおいては、拡径部111cに対する加工量が小さいので、この部分では加工硬化が生じていないか、生じていたとしても極僅かである。従って、拡径部111cの強度が比較的低く、この部分に対して曲げ加工等の後加工を行う場合であっても、加工硬化を緩和するための焼鈍処理等が不要になる。
また、差厚管Pの中間部111eおよび他端部分111fに対する加工量が大きいので、中間部111eおよび他端部分111fは加工硬化により強度が比較的高くなっている。
In the differential thickness tube P shown in FIG. 4, since the amount of work with respect to the enlarged diameter portion 111c is small, work hardening does not occur in this portion, or even if it does occur, it is very small. Therefore, the strength of the enlarged diameter portion 111c is relatively low, and even when post-processing such as bending is performed on this portion, annealing treatment or the like for alleviating work hardening becomes unnecessary.
Further, since the amount of processing of the differential thickness tube P with respect to the intermediate portion 111e and the other end portion 111f is large, the strength of the intermediate portion 111e and the other end portion 111f is relatively high due to work hardening.

以上説明の本実施形態の差厚管の製造装置と、これを用いた差厚管の製造法によれば、幅広い加工条件に応じて柔軟に対応することが可能になる。この点について、図5を用いて以下に詳説する。図5は、本実施形態の製造方法を説明するために従来の製造方法と対比した部分拡大断面図であって、(a)が従来の製造方法を示し、(b)が本実施形態の製造方法を示す。また、図5(a)の矢印A1は、素管Wの内周面がプラグ本体30より受ける面圧を示す。さらに、図5(b)の矢印A2は、素管Wの内周面がスリーブ40より受ける面圧を示す。 According to the differential pipe manufacturing apparatus of the present embodiment described above and the differential pipe manufacturing method using the same, it is possible to flexibly respond to a wide range of processing conditions. This point will be described in detail below with reference to FIG. 5A and 5B are partially enlarged cross-sectional views in comparison with the conventional manufacturing method for explaining the manufacturing method of the present embodiment, in which FIG. 5A shows the conventional manufacturing method and FIG. 5B shows the manufacturing of the present embodiment. The method is shown. Further, the arrow A1 in FIG. 5A indicates the surface pressure that the inner peripheral surface of the raw tube W receives from the plug main body 30. Further, the arrow A2 in FIG. 5B indicates the surface pressure that the inner peripheral surface of the raw tube W receives from the sleeve 40.

まず、従来の製造装置及び製造方法の場合、図5(a)に示すように、プラグ本体30に逃げ部35が形成されているものの、スリーブ40で覆われてはいない。もし、この逃げ部35の、軸線CLを含む断面における厚み寸法が大きすぎると、素管Wの内周面と小径基端部33の外周面との間における隙間寸法も大きくなる。その結果、しごき加工工程でプラグ本体30が素管Wに与える軸力に負けて係止部1e1が縮径方向に変形し、テーパー凹部11cとの係止が外れてしまう虞がある。この場合、しごき加工中の素管Wがダイス10内で滑ってしまい、しごき加工を継続できない上に、プラグ本体30の引き抜きも困難になる。 First, in the case of the conventional manufacturing apparatus and manufacturing method, as shown in FIG. 5A, although the relief portion 35 is formed in the plug main body 30, it is not covered with the sleeve 40. If the thickness dimension of the relief portion 35 in the cross section including the axis CL is too large, the gap dimension between the inner peripheral surface of the raw pipe W and the outer peripheral surface of the small diameter base end portion 33 also becomes large. As a result, the locking portion 1e1 may be deformed in the diameter reduction direction due to the axial force applied to the raw pipe W by the plug body 30 in the ironing process, and the locking portion with the tapered recess 11c may be released. In this case, the raw pipe W during the ironing process slips in the die 10, the ironing process cannot be continued, and it becomes difficult to pull out the plug body 30.

一方、逃げ部35の大きさが小さすぎると、素管Wの内周面が小径基端部33の外周面に摺接するため、素管Wの外周面とダイス10の内周面との間における摩擦力F1と、素管Wの内周面とプラグ本体30の外周面との間における摩擦力F2との力関係によって成形可否が左右される。摩擦力F2は、プラグ本体30に接する素管Wの内周面に対し、これを紙面左側に引きずる力として与えられる。一方、係止部1e1では素管Wの外周面に対し、これを止めるために紙面右側に向かって加わる力として与えられる。したがって、図5(a)に示す従来の場合は、摩擦力F1と摩擦力F2とが互いに逆向きである。
そのため、摩擦力F1と摩擦力F2とのバランスが適切になるように、両者間の摩擦係数差を調整する必要がある。具体的には、素管Wの外周面とダイス10の内周面との間における潤滑剤と、素管Wの内周面とプラグ本体30の外周面との間における潤滑剤とを互いに別物にして、摩擦力F2が摩擦力F1を上回らないようにする。
On the other hand, if the size of the relief portion 35 is too small, the inner peripheral surface of the raw pipe W is in sliding contact with the outer peripheral surface of the small diameter base end portion 33, so that between the outer peripheral surface of the raw pipe W and the inner peripheral surface of the die 10. The formability depends on the force relationship between the frictional force F1 in the above and the frictional force F2 between the inner peripheral surface of the raw tube W and the outer peripheral surface of the plug body 30. The frictional force F2 is given as a force for dragging the inner peripheral surface of the raw pipe W in contact with the plug body 30 to the left side of the paper surface. On the other hand, the locking portion 1e1 is applied to the outer peripheral surface of the raw tube W as a force applied toward the right side of the paper surface to stop the locking portion 1e1. Therefore, in the conventional case shown in FIG. 5A, the frictional force F1 and the frictional force F2 are opposite to each other.
Therefore, it is necessary to adjust the difference in friction coefficient between the friction force F1 and the friction force F2 so that the balance is appropriate. Specifically, the lubricant between the outer peripheral surface of the raw pipe W and the inner peripheral surface of the die 10 and the lubricant between the inner peripheral surface of the raw pipe W and the outer peripheral surface of the plug body 30 are different from each other. The frictional force F2 does not exceed the frictional force F1.

このように、逃げ部35の大きさや素管W内外と金型との間における摩擦係数差といった成形条件は成形可否を左右するため、幅広い加工条件に応じて柔軟に対応するためには、そのケースごとに適切な成形条件を得ておく必要がある。これに対し、本実施形態では、プラグ20の構成とその用い方とにより、成形条件の制限を大幅に緩めることを可能としている。よって、より簡易な製造方法により、差厚管Pを製造可能としている。 In this way, molding conditions such as the size of the relief portion 35 and the difference in friction coefficient between the inside and outside of the raw tube W and the mold affect whether or not molding is possible. Therefore, in order to flexibly respond to a wide range of processing conditions, It is necessary to obtain appropriate molding conditions for each case. On the other hand, in the present embodiment, it is possible to significantly relax the restrictions on the molding conditions depending on the configuration of the plug 20 and how to use the plug 20. Therefore, the differential thickness tube P can be manufactured by a simpler manufacturing method.

具体的に説明すると、図5(b)に示す本実施形態では、逃げ部35を大きめにしているものの、この逃げ部35がスリーブ40により覆われているため、素管Wの内周面はプラグ本体30ではなくスリーブ40の外周面に対して接している。すなわち、係止部1e1の内周面をスリーブ40の外周面により支えている。この時点では、スリーブ40の軸線CLに沿った位置は固定されており、しごき加工のために、プラグ本体30のみが軸線CLに沿って紙面左側へと進んでいく。 More specifically, in the present embodiment shown in FIG. 5B, although the relief portion 35 is made larger, since the relief portion 35 is covered by the sleeve 40, the inner peripheral surface of the raw pipe W is formed. It is in contact with the outer peripheral surface of the sleeve 40 instead of the plug body 30. That is, the inner peripheral surface of the locking portion 1e1 is supported by the outer peripheral surface of the sleeve 40. At this point, the position of the sleeve 40 along the axis CL is fixed, and only the plug body 30 advances to the left side of the paper surface along the axis CL due to ironing.

プラグ本体30の進行により、そのテーパー先端部31及び大径部32が素管Wの内周面に対してこれを紙面左側に引きずる力を与える。この力は、スリーブ40に接する素管Wの接触位置にも伝わるが、スリーブ40は既に位置が固定されているので、素管Wが引きずられていくのを引き留める摩擦力F2が生じる。この図5(b)における摩擦力F2は、図5(a)における摩擦力F2とは逆向きになる。このような逆向きの摩擦力F2が素管Wの内周面に与え続けられることにより、ダイス10のテーパー凹部11cに対する係止部1e1の係止状態が維持される。これに加えて、プラグ本体30を進めていっても素管Wの内周面に対する接触領域は増えないため、プラグ本体30を推し進めるための加工力が大幅に増していくこともない。 As the plug body 30 progresses, the tapered tip portion 31 and the large diameter portion 32 give a force to drag the inner peripheral surface of the raw tube W to the left side of the paper surface. This force is also transmitted to the contact position of the raw tube W in contact with the sleeve 40, but since the position of the sleeve 40 is already fixed, a frictional force F2 is generated to hold the raw tube W from being dragged. The frictional force F2 in FIG. 5B is opposite to the frictional force F2 in FIG. 5A. By continuing to apply such a frictional force F2 in the opposite direction to the inner peripheral surface of the raw pipe W, the locked state of the locking portion 1e1 with respect to the tapered recess 11c of the die 10 is maintained. In addition to this, even if the plug body 30 is advanced, the contact area with respect to the inner peripheral surface of the raw tube W does not increase, so that the processing force for advancing the plug body 30 does not increase significantly.

以上説明のように、本実施形態の差厚管の製造装置は、中空大径部11b(拡形凹部)の、プラグ本体30の押し込み方向に沿った先端側に、押し込み方向に向かって内形が先細りとなるテーパー凹部11cが形成され;前記制御部(留置機構)が、少なくとも、素管Wの一端部Wa側よりテーパー凹部11cの押し込み方向に沿った先端位置までを含む範囲を支える位置に、スリーブ40を留置する構成を採用している。そして、本実施形態の差厚管の製造装置及び製造方法は、係止工程において、拡形部1cに、プラグ本体30の押し込み方向に向かって内形(内径)が先細りとなる係止部1e1(テーパー部)を形成する。また、しごき加工工程において、少なくとも、素管Wの一端部Wa側より係止部1e1の押し込み方向に沿った先端位置までの範囲における内面を、スリーブ40により支えている。これにより、しごき加工中に素管Wがダイス10内で滑りを生じることなく、しかも大きな軸力を必要としない。よって、加圧力の小さな製造装置でも、差厚管Pを製造可能としている。 As described above, the thickness difference tube manufacturing apparatus of the present embodiment has an inner shape of the hollow large-diameter portion 11b (expanded recess) toward the tip side of the plug body 30 along the pushing direction and toward the pushing direction. A tapered recess 11c is formed so that the taper recess 11c is formed; at a position where the control unit (detention mechanism) supports at least a range including from one end Wa side of the raw pipe W to the tip position along the pushing direction of the tapered recess 11c. , The structure in which the sleeve 40 is indwelled is adopted. Then, in the manufacturing apparatus and manufacturing method of the differential thickness tube of the present embodiment, in the locking step, the locking portion 1e1 whose inner shape (inner diameter) tapers toward the expanding portion 1c in the pushing direction of the plug main body 30. (Tapered portion) is formed. Further, in the ironing process, the sleeve 40 supports at least the inner surface in the range from one end Wa side of the raw pipe W to the tip position along the pushing direction of the locking portion 1e1. As a result, the raw pipe W does not slip in the die 10 during the ironing process, and a large axial force is not required. Therefore, the differential thickness tube P can be manufactured even with a manufacturing apparatus having a small pressing force.

なお、スリーブ40の適切な固定位置としては、スリーブ40の先端が、図5(b)に示すように、ダイス10のテーパー凹部11cのうちで最も径の大きい後端位置P1に達していることが必須であり、テーパー凹部11cのうちで最も径の小さい先端位置P2に達していることが好ましく、さらには、先端位置P2よりもさらに押し込み方向奥側の位置P3に達していることがより好ましい。ここで、軸線CLに沿って見て後端位置P1を基準(l1=0mm)とし、さらにこの後端位置P1からプラグ本体30の押し込み方向に沿ったスリーブ40の先端の位置をl1(mm)とした場合、このl1(mm)が0mm以上であることが好ましい。また、このl1(mm)の上限値は50mmであり、より好ましくは10mmである。
すなわち、図1(c)に示すように、しごき加工工程では、素管Wの一端部Wa側から係止部1e1の後端位置P1までのl2(mm)の部分と、前記l1(mm)の部分とを合算したLx(mm)の範囲における内周面を、スリーブ40の外周面によって支える。言い換えると、素管Wの一端部Wa側からテーパー凹部11cの後端位置P1までの間であるl2(mm)の部分と、後端位置P1からプラグ本体30の押し込み方向に沿った50mm以下の位置までのl1(mm)の部分との双方に重なる位置に、前記留置機構がスリーブ40を留置する。好ましい場合は、0〜50mm、より好ましくは、0〜10mmである。
As an appropriate fixing position of the sleeve 40, as shown in FIG. 5B, the tip of the sleeve 40 reaches the rear end position P1 having the largest diameter among the tapered recesses 11c of the die 10. Is essential, and it is preferable that the tip position P2 having the smallest diameter among the tapered recesses 11c is reached, and further, it is more preferable that the tip position P3 is further located on the back side in the pushing direction than the tip position P2. .. Here, the rear end position P1 is used as a reference (l1 = 0 mm) when viewed along the axis CL, and the position of the tip of the sleeve 40 along the pushing direction of the plug body 30 from this rear end position P1 is l1 (mm). , It is preferable that this l1 (mm) is 0 mm or more. The upper limit of l1 (mm) is 50 mm, more preferably 10 mm.
That is, as shown in FIG. 1 (c), in the ironing process, the portion of l2 (mm) from the one end Wa side of the raw pipe W to the rear end position P1 of the locking portion 1e1 and the l1 (mm). The inner peripheral surface in the range of Lx (mm) including the portion of the sleeve 40 is supported by the outer peripheral surface of the sleeve 40. In other words, the portion of l2 (mm) between one end Wa side of the raw pipe W and the rear end position P1 of the tapered recess 11c, and 50 mm or less along the pushing direction of the plug body 30 from the rear end position P1. The indwelling mechanism indwells the sleeve 40 at a position overlapping both the l1 (mm) portion up to the position. It is preferably 0 to 50 mm, more preferably 0 to 10 mm.

以下、本発明の効果を確認するために、図6(a)に示す発明例と、図6(b)に示す比較例とのそれぞれに対し、数値解析により、素管(鋼管)の滑り有無としごき加工に要した軸力(加工力)とを求めて対比した。なお、「すべり量」は、鋼管のしごき開始位置からの端部移動量(図6(b)の符号s参照)として定義した。また、「工具と鋼管の隙間」は、図6(b)の比較例では、符号gに示すように、小径基端部33の外周面と素管Wの内周面との間の寸法(逃げ部35の寸法に等しい)と規定した。一方、図6(a)の発明例では、符号gに示すように、スリーブ40の外周面と素管Wの内周面との間の寸法(逃げ部35の寸法に等しい)を、「工具と鋼管の隙間」と規定した。
また、「減肉量」は、素管Wの肉厚から減肉部の肉厚を差し引いた寸法(図6の(a)及び(b)に示す符号r)と規定した。
Hereinafter, in order to confirm the effect of the present invention, the presence or absence of slippage of the raw pipe (steel pipe) is performed by numerical analysis on each of the invention example shown in FIG. 6 (a) and the comparative example shown in FIG. 6 (b). The axial force (machining force) required for the ironing process was calculated and compared. The "slip amount" was defined as the amount of movement of the end of the steel pipe from the ironing start position (see reference numeral s in FIG. 6B). Further, in the comparative example of FIG. 6B, the “gap between the tool and the steel pipe” is the dimension between the outer peripheral surface of the small diameter base end portion 33 and the inner peripheral surface of the raw pipe W, as shown by reference numeral g. Equal to the size of the relief section 35). On the other hand, in the invention example of FIG. 6A, as shown by reference numeral g, the dimension between the outer peripheral surface of the sleeve 40 and the inner peripheral surface of the raw pipe W (equal to the dimension of the relief portion 35) is set to “tool”. And the gap between steel pipes. "
Further, the "thickening amount" is defined as the dimension obtained by subtracting the wall thickness of the thinned portion from the wall thickness of the raw tube W (reference numeral r shown in FIGS. 6A and 6).

以上の規定の下、下記条件で数値解析を行った。
・使用解析ソフト:Abaqus/Explicit
・軸対称として仮定
・ダイスの内周面と素管の外周面との間の摩擦係数をμDとし、さらにμD=0.25に固定
・プラグの外周面及び素管の内周面間の摩擦係数と、スリーブの外周面及び素管の内周面間の摩擦係数とのそれぞれを、等しくμPと規定
・摩擦係数μPと摩擦係数μD間の摩擦係数差△μを、△μ=μD−μPと規定
・素管素材:440MPa級鋼管
・素管形状:外径60.5mmの円管で肉厚が1.8mm
・差厚管形状:肉厚1.8mmを0.9mmに減肉。拡管部の拡管量は3%とする
Under the above rules, numerical analysis was performed under the following conditions.
-Analysis software used: Abaqus / Explicit
・ Assumed to be axially symmetric ・ The coefficient of friction between the inner peripheral surface of the die and the outer peripheral surface of the raw pipe is set to μD, and further fixed at μD = 0.25 ・ Friction between the outer peripheral surface of the plug and the inner peripheral surface of the raw pipe The coefficient and the friction coefficient between the outer peripheral surface of the sleeve and the inner peripheral surface of the raw pipe are defined as μP, respectively. ・ The friction coefficient difference between the friction coefficient μP and the friction coefficient μD is Δμ = μD−μP.・ Raw pipe material: 440 MPa class steel pipe ・ Raw pipe shape: Circular pipe with an outer diameter of 60.5 mm and a wall thickness of 1.8 mm
・ Difference thickness tube shape: The wall thickness is reduced from 1.8 mm to 0.9 mm. The amount of pipe expansion in the pipe expansion part shall be 3%.

解析結果を、図7及び図8に示す。図7は、数値解析の結果を示すグラフであり、(a)が従来の製造方法の場合を示し、(b)が本実施形態の製造方法の場合を示す。図8は、数値解析の結果を示す他のグラフであり、(a)が従来の製造方法の場合を示し、(b)が本実施形態の製造方法の場合を示す。 The analysis results are shown in FIGS. 7 and 8. 7A and 7B are graphs showing the results of numerical analysis, in which FIG. 7A shows the case of the conventional manufacturing method and FIG. 7B shows the case of the manufacturing method of the present embodiment. 8A and 8B are other graphs showing the results of numerical analysis, in which FIG. 8A shows the case of the conventional manufacturing method and FIG. 8B shows the case of the manufacturing method of the present embodiment.

図7は、横軸が、工具と鋼管の隙間を減肉量で除算した無次元値を示し、縦軸が摩擦係数差△μを示す。また、○印は滑り無し(滑り量がゼロ)、白三角印が滑り量15mm未満、黒三角印が滑り量15mm以上をそれぞれ示す。
図7では、紙面右下に向かうほど条件が厳しくなる傾向にあるが、滑り無く加工できる範囲が、比較例である図7(a)の場合よりも発明例である図7(b)の方が広がっていることが確認された。
In FIG. 7, the horizontal axis shows a dimensionless value obtained by dividing the gap between the tool and the steel pipe by the amount of wall thinning, and the vertical axis shows the friction coefficient difference Δμ. In addition, ○ marks indicate no slippage (slip amount is zero), white triangle marks indicate slippage amount of less than 15 mm, and black triangle marks indicate slip amount of 15 mm or more.
In FIG. 7, the conditions tend to be stricter toward the lower right of the paper surface, but the range in which processing can be performed without slipping is in FIG. 7 (b), which is an invention example, than in the case of FIG. 7 (a), which is a comparative example. Was confirmed to be widespread.

図8は、横軸が、工具と鋼管の隙間を減肉量で除算した無次元値であり、縦軸が加工力(kN)を示している。
図8(a)に示す比較例に比べて、図8(b)に示す発明例では、必要とされる加工力が大幅に低減されていることが確認された。また、発明例では、工具と鋼管の隙間を減肉量で除算した無次元値に左右されることなく、加工力が一定であった。
In FIG. 8, the horizontal axis is a dimensionless value obtained by dividing the gap between the tool and the steel pipe by the amount of wall reduction, and the vertical axis is the machining force (kN).
It was confirmed that the required processing force was significantly reduced in the invention example shown in FIG. 8 (b) as compared with the comparative example shown in FIG. 8 (a). Further, in the invention example, the machining force was constant without being influenced by the dimensionless value obtained by dividing the gap between the tool and the steel pipe by the amount of wall reduction.

以上に説明した実施形態及び実施例は一例であり、その趣旨を逸脱しない限り、種々の変更が可能である。
例えば上記実施形態では、スリーブ40をダイス10内に固定して留置するための機構として、前記プラグ駆動部を前記制御部により停止させる構成としたが、これに代えて、図9に示すプラグ20Aを採用してもよい。このプラグ20Aのスリーブ40Aは、前記スリーブ40と比べて、唾状の係止部43Aをその後端位置に備えた点のみが異なっている。一方、プラグ本体30は上述の構成と同じである。このプラグ20Aによれば、スリーブ40の軸線CLに沿った位置が適切な停止位置に至ったときに係止部43Aがダイス10に対して係止し、それ以上のスリーブ40の進行を止めるように位置固定することができる。この構成によれば、より簡単な構成でスリーブ40を適切な位置に固定することができる。
The embodiments and examples described above are examples, and various changes can be made as long as they do not deviate from the purpose.
For example, in the above embodiment, as a mechanism for fixing and indwelling the sleeve 40 in the die 10, the plug drive unit is stopped by the control unit, but instead of this, the plug 20A shown in FIG. 9 May be adopted. The sleeve 40A of the plug 20A differs from the sleeve 40 only in that a saliva-shaped locking portion 43A is provided at the rear end position. On the other hand, the plug body 30 has the same configuration as described above. According to this plug 20A, when the position of the sleeve 40 along the axis CL reaches an appropriate stop position, the locking portion 43A locks with respect to the die 10 and stops the further progress of the sleeve 40. Can be fixed in position. According to this configuration, the sleeve 40 can be fixed in an appropriate position with a simpler configuration.

上記実施形態では、素管W及び差厚管Pを、内形及び外形ともに円形としたが、円形のみに限らずその他の形状を採用してもよい。例えば、図10(a)〜(e)に示す断面形状を採用してもよい。例えば図10(a)では、外形が円形状で内形が略四角形状である。また、図10(b)では、外形が円形状で内形が楕円形状である。また、図10(c)は紙面上下方向に沿った仮想直線を境として線対称形状を有しており、具体的には、外形が円形状で内形が略四角形状でかつ互いに対向する一対の辺のそれぞれに凹所が形成されている。また、図10(d)では、外形が略四角形状でかつ内形が円形状である。また、図10(e)では、外形が楕円形状でかつ内形が円形状である。 In the above embodiment, the raw pipe W and the differential thickness pipe P are circular in both the inner shape and the outer shape, but the shape is not limited to the circular shape and other shapes may be adopted. For example, the cross-sectional shapes shown in FIGS. 10A to 10E may be adopted. For example, in FIG. 10A, the outer shape is circular and the inner shape is substantially quadrangular. Further, in FIG. 10B, the outer shape is circular and the inner shape is elliptical. Further, FIG. 10C has a line-symmetrical shape with a virtual straight line along the vertical direction of the paper surface as a boundary. Specifically, a pair having a circular outer shape, a substantially quadrangular inner shape, and facing each other. A recess is formed on each side of the. Further, in FIG. 10D, the outer shape is substantially quadrangular and the inner shape is circular. Further, in FIG. 10E, the outer shape is an elliptical shape and the inner shape is a circular shape.

ダイス10の収容部の一部である中空小径部11aの断面形状と、プラグ本体30の大径部32の断面形状とを適宜組み合わせることにより、例えば図10(a)〜(e)に示したような断面形状を得ることができる。すなわち、プラグ本体30の押し込み方向(軸線CLに沿った方向)に垂直な断面で見た場合、中空小径部11aの断面形状が、円形、楕円形、矩形、線対称形状、のうちの何れかであり、大径部32の断面形状が、円形、楕円形、矩形、線対称形状、のうちの何れかであるとする。そして、中空小径部11aの断面形状と大径部32の断面形状とを適宜組み合わせることにより、様々な断面形状を得ることができる。 By appropriately combining the cross-sectional shape of the hollow small-diameter portion 11a, which is a part of the accommodating portion of the die 10, and the cross-sectional shape of the large-diameter portion 32 of the plug main body 30, for example, FIGS. 10A to 10E are shown. Such a cross-sectional shape can be obtained. That is, when viewed in a cross section perpendicular to the pushing direction of the plug body 30 (direction along the axis CL), the cross-sectional shape of the hollow small diameter portion 11a is any one of circular, elliptical, rectangular, and axisymmetric. It is assumed that the cross-sectional shape of the large-diameter portion 32 is any of a circular shape, an elliptical shape, a rectangular shape, and a line-symmetrical shape. Then, various cross-sectional shapes can be obtained by appropriately combining the cross-sectional shape of the hollow small-diameter portion 11a and the cross-sectional shape of the large-diameter portion 32.

上記実施形態では、素管Wの一端部Wa側からのみ、プラグ20を入れてしごき加工を行うものとしたが、この構成に限らない。例えば、素管Wが長尺の場合、その一端部Wa側からプラグ20を入れてしごき加工を行った後、続けて、その他端部Wb側からプラグ20を入れて同様のしごき加工を行ってもよい。 In the above embodiment, the plug 20 is inserted and ironed only from one end Wa side of the raw tube W, but the present invention is not limited to this configuration. For example, when the raw pipe W is long, the plug 20 is inserted from one end Wa side and ironing is performed, and then the plug 20 is inserted from the other end Wb side and the same ironing is performed. May be good.

本実施形態の製造方法により製造された差厚管Pの適用例としては、自動車部品ではクロスメンバー、サスペンションメンバー、サスペンションアームなどのフレーム部材、およびペリメーターやサイドインパクトバーなどの衝突対応部品、またはドライブシャフトなどの駆動系パイプ部品が挙げられる。
クロスメンバー、サスペンションアーム、サスペンションメンバーなどのフレーム部材では、他部品の取り付け部分に特に肉厚が要求されるケースが多い為、本発明の各実施形態における差厚管を用いれば、必要な箇所のみを厚肉化した軽量な構造を採用することができる。また、これらの部品において、その厚肉部を所定の形状に成形する後加工の際に、プレス加工や曲げ加工が施される場合がある。この場合、加工が施される部分が厚肉かつ低強度であると加工しやすいため、本発明の各実施形態における差厚管を好適に用いることができる。
As an application example of the differential thickness pipe P manufactured by the manufacturing method of the present embodiment, in automobile parts, frame members such as cross members, suspension members and suspension arms, and collision-responsive parts such as perimeters and side impact bars, or Examples include drive system pipe parts such as drive shafts.
In frame members such as cross members, suspension arms, and suspension members, there are many cases where a wall thickness is particularly required for the mounting portion of other parts. Therefore, if the differential thickness pipe in each embodiment of the present invention is used, only the necessary portion is required. A lightweight structure with a thicker wall can be adopted. Further, in these parts, press working or bending may be performed at the time of post-processing for forming the thick portion into a predetermined shape. In this case, if the portion to be processed is thick and has low strength, it is easy to process, so that the differential thickness tube according to each embodiment of the present invention can be preferably used.

サイドインパクトバーは、ドアパネル内に設置され、衝突の際の衝突エネルギーをドアの両サイドに伝達する部材であり、衝突時に折損しないことが望まれる。そのため、本発明の各実施形態における差厚管を用いて中央部を厚肉化すれば、軽量な構造とすることができる。
ペリメーターは、車体前部のフレーム部材であり、前面衝突時の荷重伝達経路となる部材であるが、衝突時に屈曲し易い曲がり形状部などを厚肉部とすることで、より軽量化できる。また、厚肉部を曲げ加工する際には、この厚肉部が低強度であると加工しやすいため、本発明の各実施形態における差厚管を好適に用いることができる。
ドライブシャフトは、管端の差厚部にスプライン加工を行う場合があり、この部分が厚肉かつ低強度であると加工がしやすいため、本発明の各実施形態における差厚管を好適に用いることができる。
The side impact bar is a member installed in the door panel and transmits the collision energy at the time of a collision to both sides of the door, and it is desired that the side impact bar does not break at the time of a collision. Therefore, if the central portion is thickened by using the difference thickness pipe in each embodiment of the present invention, a lightweight structure can be obtained.
The perimeter is a frame member at the front of the vehicle body and is a member that serves as a load transmission path at the time of a frontal collision. However, the weight can be further reduced by making a bent-shaped portion that is easily bent at the time of a collision a thick portion. Further, when bending a thick portion, if the thick portion has a low strength, it is easy to process, so that the differential thickness pipe according to each embodiment of the present invention can be preferably used.
The drive shaft may be splined at the difference thickness portion of the pipe end, and if this portion is thick and has low strength, it is easy to process. Therefore, the difference thickness pipe according to each embodiment of the present invention is preferably used. be able to.

1c 拡形部
1e1 テーパー部
10 ダイス
11b 中空大径部(拡形凹部)
11c テーパー凹部
30 プラグ本体
35 逃げ部
40 スリーブ
43A 係止部(留置機構、係止部)
P 差厚管
W 素管
Wa 一端
Wb 他端
1c Enlarged part 1e1 Tapered part 10 Die 11b Hollow large diameter part (expanded recess)
11c Tapered recess 30 Plug body 35 Relief part 40 Sleeve 43A Locking part (detention mechanism, locking part)
P differential pipe W raw pipe Wa one end Wb other end

Claims (14)

中空筒状の素管より差厚管を製造する方法であって、
前記素管をダイス内に配置し、前記素管の長手方向への移動を規制した状態で、前記素管の一端側よりプラグ本体をスリーブと共に押し込み、前記一端側の外形を拡大させた拡形部を形成し、前記拡形部を前記ダイスに係止させる係止工程と;
前記素管の前記規制を解く一方で前記素管の前記係止は維持してかつ、前記拡形部の内面を、前記スリーブで支えた状態で、
前記プラグ本体をさらに前記素管の他端側に向かって押し込み、前記素管の外形を維持したまま内形を拡げるしごき加工を行う、しごき加工工程と;
を有することを特徴とする、差厚管の製造方法。
It is a method of manufacturing a differential thickness tube from a hollow tubular raw tube.
With the raw pipe placed in the die and the movement of the raw pipe in the longitudinal direction is restricted, the plug body is pushed together with the sleeve from one end side of the raw pipe to expand the outer shape of the one end side. With a locking step of forming a portion and locking the expanded portion to the die;
While releasing the regulation of the raw pipe, the locking of the raw pipe is maintained, and the inner surface of the enlarged portion is supported by the sleeve.
In the ironing process, the plug body is further pushed toward the other end side of the raw pipe, and the inner shape is expanded while maintaining the outer shape of the raw pipe.
A method for manufacturing a differential thickness pipe, which comprises.
前記係止工程で、前記拡形部に、前記プラグ本体の押し込み方向に向かって外形が先細りとなるテーパー部が形成され;
前記しごき加工工程で、少なくとも、前記素管の前記一端側より前記テーパー部の前記押し込み方向に沿った後端位置までの範囲における前記拡形部の内面を、前記スリーブにより支える;
ことを特徴とする、請求項1に記載の差厚管の製造方法。
In the locking step, a tapered portion whose outer shape is tapered in the pushing direction of the plug body is formed in the expanded portion;
In the ironing process, the sleeve supports the inner surface of the enlarged portion at least in the range from one end side of the raw pipe to the rear end position of the tapered portion along the pushing direction of the tapered portion;
The method for manufacturing a differential thickness tube according to claim 1, wherein the difference thickness tube is manufactured.
前記しごき加工工程で、前記スリーブによって前記拡形部の内面を支える際の前記範囲が、前記後端位置より前記押し込み方向に沿って50mm以下の位置までである
ことを特徴とする、請求項2に記載の差厚管の製造方法。
2. The method according to claim 2, wherein in the ironing process, the range when the inner surface of the enlarged portion is supported by the sleeve is from the rear end position to a position of 50 mm or less along the pushing direction. The method for manufacturing a differential thick tube according to.
前記しごき加工工程で、前記スリーブを、前記ダイスに係止させて位置固定する
ことを特徴とする、請求項1〜3の何れか1項に記載の差厚管の製造方法。
The method for manufacturing a differential thick tube according to any one of claims 1 to 3, wherein in the ironing process, the sleeve is locked to the die to fix the position.
前記素管及び前記差厚管が共に円管であり;
前記素管の外径寸法をD1(mm)、前記拡形部の外径寸法をD2(mm)として、下記式1で示される拡径量EXが0.1%〜50%である;
ことを特徴とする、請求項1〜4の何れか1項に記載の差厚管の製造方法。
Ex(%)=(D2−D1)/D1×100・・・(式1)
Both the raw pipe and the difference thickness pipe are circular pipes;
Assuming that the outer diameter of the raw pipe is D1 (mm) and the outer diameter of the enlarged portion is D2 (mm), the diameter expansion amount EX represented by the following formula 1 is 0.1% to 50%;
The method for manufacturing a differential thickness tube according to any one of claims 1 to 4, wherein the difference thickness tube is manufactured.
Ex (%) = (D2-D1) / D1 × 100 ... (Equation 1)
前記しごき加工工程後の、前記差厚管の減肉部における減肉率が10%〜90%の範囲内である
ことを特徴とする、請求項5に記載の差厚管の製造方法。
The method for manufacturing a thickened pipe according to claim 5, wherein the thinning rate in the thinned portion of the thickened pipe after the ironing process is in the range of 10% to 90%.
前記素管としてシームレス鋼管を用いることを特徴とする、請求項1〜6の何れか一項に記載の差厚管の製造方法。 The method for manufacturing a differential thickness pipe according to any one of claims 1 to 6, wherein a seamless steel pipe is used as the raw pipe. 中空筒状の素管より差厚管を製造する装置であって、
前記素管を収容するとともに前記素管の外形よりも大きな拡形凹部を含む収容部を有するダイスと;
前記収容部内の前記素管の一端側に対して挿抜されるプラグ本体及びスリーブと;
前記プラグ本体及び前記スリーブの挿抜を行う駆動機構と;
前記スリーブを前記拡形凹部内に留める留置機構と;
を備えることを特徴とする、差厚管の製造装置。
It is a device that manufactures a differential thickness tube from a hollow tubular raw tube.
With a die that accommodates the raw pipe and has an accommodating portion that includes an enlarged recess larger than the outer shape of the raw pipe;
With the plug body and sleeve that are inserted and removed from one end side of the raw pipe in the accommodating portion;
With a drive mechanism for inserting and removing the plug body and the sleeve;
With an indwelling mechanism that fastens the sleeve in the enlarged recess;
A device for manufacturing a differential thickness tube, which comprises.
前記プラグ本体が、前記プラグ本体の先端部よりも外形の小さい逃げ部を前記先端部よりも後端側の位置に有し;
前記逃げ部を被覆可能に、前記スリーブが前記プラグ本体に対して外挿されている;
ことを特徴とする、請求項8に記載の差厚管の製造装置。
The plug body has a relief portion having a smaller outer shape than the tip portion of the plug body at a position on the rear end side of the tip portion;
The sleeve is extrapolated to the plug body so that the relief can be covered;
The apparatus for manufacturing a differential thickness tube according to claim 8.
前記拡形凹部の、前記プラグ本体の押し込み方向に沿った先端側に、前記押し込み方向に向かって内形が先細りとなるテーパー凹部が形成され;
前記留置機構が、少なくとも、前記素管の前記一端側より前記テーパー凹部の前記押し込み方向に沿った後端位置までを含む範囲に重なる位置に、前記スリーブを留置する;
ことを特徴とする、請求項8または9に記載の差厚管の製造装置。
A tapered recess is formed on the tip side of the expanded recess along the pushing direction of the plug body so that the inner shape is tapered toward the pushing direction;
The sleeve is indwelled at a position where the indwelling mechanism overlaps at least in a range including from one end side of the raw pipe to the rear end position of the tapered recess along the pushing direction;
The apparatus for manufacturing a differential thickness tube according to claim 8 or 9, wherein the thickness difference tube is manufactured.
前記素管の前記一端側から前記拡形凹部の前記後端位置までの間と、前記後端位置から前記プラグ本体の押し込み方向に沿った50mm以下の位置までの間とに重なる位置に、前記留置機構が前記スリーブを留置する
ことを特徴とする、請求項10に記載の差厚管の製造装置。
At a position overlapping between the one end side of the raw pipe and the rear end position of the expanded recess and the position of 50 mm or less along the pushing direction of the plug body from the rear end position. The device for manufacturing a differential thickness tube according to claim 10, wherein the indwelling mechanism indwells the sleeve.
前記留置機構が、前記スリーブに設けられて前記ダイスに係止する係止部である
ことを特徴とする、請求項8〜11の何れか1項に記載の差厚管の製造装置。
The device for manufacturing a differential thickness tube according to any one of claims 8 to 11, wherein the indwelling mechanism is a locking portion provided on the sleeve and locked to the die.
前記留置機構が、前記スリーブの挿抜停止位置を前記駆動機構に指示する制御部である;
ことを特徴とする、請求項8〜11の何れか1項に記載の差厚管の製造装置。
The indwelling mechanism is a control unit that instructs the drive mechanism of the insertion / removal stop position of the sleeve;
The apparatus for manufacturing a differential thickness tube according to any one of claims 8 to 11, characterized in that.
前記プラグ本体の押し込み方向に垂直な断面で見た場合、
前記収容部の形状が、円形、楕円形、矩形、線対称形状、のうちの何れかであり、
前記プラグ本体の形状が、円形、楕円形、矩形、線対称形状、のうちの何れかである
ことを特徴とする、請求項8〜13の何れか1項に記載の差厚管の製造装置。
When viewed in a cross section perpendicular to the pushing direction of the plug body,
The shape of the accommodating portion is any of a circular shape, an elliptical shape, a rectangular shape, and a line-symmetrical shape.
The apparatus for manufacturing a differential thickness tube according to any one of claims 8 to 13, wherein the shape of the plug body is any one of a circular shape, an elliptical shape, a rectangular shape, and a line-symmetrical shape. ..
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JP7513890B2 (en) 2020-11-11 2024-07-10 日本製鉄株式会社 DESIGN ASSISTANCE APPARATUS, DESIGN ASSISTANCE METHOD, AND DESIGN ASSISTANCE PROGRAM

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JP7513890B2 (en) 2020-11-11 2024-07-10 日本製鉄株式会社 DESIGN ASSISTANCE APPARATUS, DESIGN ASSISTANCE METHOD, AND DESIGN ASSISTANCE PROGRAM
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