JP2001018016A - Piercing method at time of hydrostatically bulging metallic tube - Google Patents

Piercing method at time of hydrostatically bulging metallic tube

Info

Publication number
JP2001018016A
JP2001018016A JP11193586A JP19358699A JP2001018016A JP 2001018016 A JP2001018016 A JP 2001018016A JP 11193586 A JP11193586 A JP 11193586A JP 19358699 A JP19358699 A JP 19358699A JP 2001018016 A JP2001018016 A JP 2001018016A
Authority
JP
Japan
Prior art keywords
piercing
die
punch
hole
bulging
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
JP11193586A
Other languages
Japanese (ja)
Other versions
JP3674393B2 (en
Inventor
Mitsutoshi Uchida
光俊 内田
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.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries 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 Sumitomo Metal Industries Ltd filed Critical Sumitomo Metal Industries Ltd
Priority to JP19358699A priority Critical patent/JP3674393B2/en
Publication of JP2001018016A publication Critical patent/JP2001018016A/en
Application granted granted Critical
Publication of JP3674393B2 publication Critical patent/JP3674393B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide a piercing method at the time of hydrostatical bulging by which metallic pieces produced by piercing are not left in a product nor in a die. SOLUTION: A die hole 17 is provided on the inner surface of a pair of dies 7, 8, a punch 12 which can be entered into and retreated from the die hole is inserted into the die hole so that its tip face forms the same plane as the inner surface of the die. On a metallic tube stock housed in the die, an expanded part 18 is formed by hydrostatic bulging, and subsequently by retreating the punch, part of the bulged part is pierced into the die hole shape by fluid pressure in the bulged part. After that, by advancing the punch, the metallic piece produced by piercing is pushed back and fit into the hole formed by piercing. After the worked product is taken out of the hydrostatically bulging device, the metallic piece fit in the hole is removed.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、金属管内に導入し
た加工液の圧力と金属管の軸方向圧縮力とを組み合わせ
て金属管に膨出部を成形し、その膨出部にピアシング
(孔あけ)加工する方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a bulge in a metal tube by combining the pressure of a working fluid introduced into the metal tube and the compressive force of the metal tube in the axial direction, and piercing the hole with the bulge. Opening) It relates to the method of processing.

【0002】[0002]

【従来の技術】液圧バルジ加工方法は、素材となる金属
管(以下金属素管と記す)内に加工液を注入し、その加
工液に負荷した圧力(以下内圧と記す)と金属管端から
の軸押し力を組み合わせることにより、種々の断面形状
の管状製品を得る加工方法で、自動車部品の成形等に利
用されている。
2. Description of the Related Art A hydraulic bulging method is based on a method in which a working fluid is poured into a metal pipe (hereinafter, referred to as a metal pipe) as a material, and a pressure (hereinafter, referred to as an internal pressure) applied to the working fluid and an end of the metal pipe. This is a processing method for obtaining tubular products having various cross-sectional shapes by combining axial pushing forces from various types, and is used for molding automotive parts and the like.

【0003】製品によっては、膨出加工部に小さな穴を
設けなければならない場合がある。鋼板等に穴を設ける
場合、一般にはダイスとポンチが使用される。しかし、
液圧バルジ加工後の形状は通常管状であり、管端近く以
外では管内部にダイスを位置させることが困難なため、
ポンチとダイスによる穴あけ加工をおこなうことはでき
ない。そこで、バルジ加工時のピアシング加工は、以下
に説明するようなバルジ加工中の内圧を利用した方法が
採用されている。
In some products, a small hole must be provided in the bulging portion. When providing a hole in a steel plate or the like, a die and a punch are generally used. But,
Since the shape after hydraulic bulging is usually tubular, it is difficult to position the dies inside the pipe except near the pipe end,
Drilling with punches and dies cannot be performed. Therefore, for piercing at the time of bulging, a method utilizing the internal pressure during bulging as described below is employed.

【0004】図1は、ピアシング加工ができる液圧バル
ジ加工装置の1例を示す図である。この装置は、ベッド
1とクラウン2は4本のコラム3で連結され、クラウン
2に固定された油圧シリンダ4のピストン5によってス
ライド6が上下する。スライドには上金型7が、ベッド
上には下金型8がそれぞれ対面させて設置されている。
また、ベッド上には下金型の両端に対面させた軸押し装
置9が設置されている。軸押し装置のシール工具10は
軸押し装置に内蔵されている油圧シリンダーにより前後
進可能となっている。
FIG. 1 is a diagram showing an example of a hydraulic bulge processing apparatus capable of performing piercing. In this device, a bed 1 and a crown 2 are connected by four columns 3, and a slide 6 is moved up and down by a piston 5 of a hydraulic cylinder 4 fixed to the crown 2. An upper mold 7 is installed on the slide, and a lower mold 8 is installed on the bed so as to face each other.
Further, an axial pushing device 9 facing both ends of the lower mold is installed on the bed. The sealing tool 10 of the shaft pushing device can be moved forward and backward by a hydraulic cylinder built in the shaft pushing device.

【0005】上下の金型を合わせた場合のダイス内面1
1a、11bの形状は、製品の外形と同じ形状になって
いる。
Die inner surface 1 when upper and lower dies are combined
The shapes of 1a and 11b are the same as the outer shape of the product.

【0006】図2は、図1の上金型部の拡大図である。
金型の内面11bにはダイス14が設けられており、ダ
イス孔に油圧シリンダー13により前後進可能なポンチ
12が挿入されている。
FIG. 2 is an enlarged view of the upper mold part of FIG.
A die 14 is provided on the inner surface 11b of the mold, and a punch 12 that can move forward and backward by a hydraulic cylinder 13 is inserted into a die hole.

【0007】先ず、下金型8の内面11aに金属素管
を、その管端がシール工具10に対面するように載置
し、上金型7を降下させて下金型に合わせて押圧する。
次いで、シール工具10を前進させて管端に押しつけ、
シール工具内に設けられている加工液導入孔20から金
属素管内に加工液を注入して加圧すると同時に、シール
工具を前進させて管軸方向に圧縮力を負荷することによ
り、金属素管を製品形状である金型内面の形状に膨出加
工する。次いで、膨出部の一部に穴をあけるピアシング
加工がおこなわれる。
First, a metal tube is placed on the inner surface 11a of the lower mold 8 such that the end of the metal tube faces the sealing tool 10, and the upper mold 7 is lowered and pressed according to the lower mold. .
Next, the sealing tool 10 is advanced and pressed against the pipe end,
The working fluid is injected into the metal blank through the working fluid introduction hole 20 provided in the sealing tool and pressurized, and at the same time, the sealing tool is advanced to apply a compressive force in the pipe axis direction, so that the metal blank is filled. Is bulged into the shape of the inner surface of the mold, which is the product shape. Next, a piercing process for making a hole in a part of the bulging portion is performed.

【0008】図3、図4および図5は、従来の三つのピ
アシング加工方法を説明するための図で、各図の(a)
は液圧バルジ加工が終了した状態を示す図、各図の
(b)はピアシング加工が完了した状態を示す図であ
る。
FIGS. 3, 4 and 5 are views for explaining three conventional piercing methods, and FIG.
Is a diagram showing a state in which hydraulic bulging is completed, and (b) of each figure is a diagram showing a state in which piercing is completed.

【0009】これら各図の(a)に示すように、下金型
8と上金型7間で上述の液圧バルジ加工方法により金属
素管に膨出部18が成形されている。これらのポンチの
位置は、液圧バルジ加工を開始する前と同じで、ポンチ
の先端面は金型の内面と同じ面を形成するように位置し
ている。
As shown in FIGS. 1A and 1B, a bulge 18 is formed between the lower mold 8 and the upper mold 7 in the metal tube by the above-described hydraulic bulging method. The positions of these punches are the same as before the start of the hydraulic bulging, and the leading end surface of the punch is located so as to form the same surface as the inner surface of the mold.

【0010】図3に示す方法では、液圧バルジ加工によ
る膨出部の成形が完了すると、図3(b)に示すように
高内圧状態のもとで、金型内のポンチ12をダイス孔1
7から押しだしてピアシング加工をおこない、膨出部に
穴をあける。したがって、この方法ではピアシング加工
で生じた金属片16は成形品内に残る。
In the method shown in FIG. 3, when the formation of the bulging portion by the hydraulic bulging process is completed, the punch 12 in the mold is inserted into the die hole under a high internal pressure state as shown in FIG. 3 (b). 1
Press out from 7 to perform piercing, and drill holes in the bulge. Therefore, in this method, the metal piece 16 generated by the piercing process remains in the molded product.

【0011】図4に示す方法では、ポンチ先端は水平で
なく僅かに傾斜しているため、ポンチ12をダイス孔か
ら押し出してピアシング加工しても、図4(b)に示す
ようにピアシングにより生じる金属片16は、一部で膨
出部と繋がった状態になる。
In the method shown in FIG. 4, since the tip of the punch is not horizontal but slightly inclined, even if the punch 12 is pushed out of the die hole and pierced, the piercing occurs as shown in FIG. 4B. The metal piece 16 is partially connected to the bulging portion.

【0012】図5に示す方法は、液圧バルジ加工後にポ
ンチを後退させることにより、内圧によりダイス孔に接
している膨出部をピアシング加工する方法であり、ピア
シング加工により生じた金属片16は金型内に残る。
The method shown in FIG. 5 is a method of piercing a bulging portion in contact with a die hole by internal pressure by retracting a punch after hydraulic bulging, and a metal piece 16 generated by the piercing is formed. Remains in the mold.

【0013】しかしながら、図3で説明した方法は、ピ
アシング加工後の金属片は成形品内に残るため、成形品
の形状が複雑な場合や管端径が金属片より小さい場合、
製品外に取り出すのが困難である。また、この方法では
金属片が製品から完全に脱離しないで付着したままとな
ることがあり、最終製品内に残った金属片が何らかの衝
撃で脱離し製品が動いたときに内部で異音が生じるとい
った問題が発生する場合がある。
However, in the method described with reference to FIG. 3, since the metal piece after the piercing process remains in the molded article, when the shape of the molded article is complicated or when the pipe end diameter is smaller than the metal piece,
Difficult to take out of the product. Also, in this method, the metal pieces may not adhere completely to the product but may remain attached, and when the product moves due to the metal pieces remaining in the final product being dislodged by some impact, noise inside the product may occur. May occur.

【0014】この問題を回避するための方法が図4に示
した方法である。しかし、この方法では金属片16を管
内に折り曲げて固定するため、ピアシングにより成形す
る穴が真円にならず、また金属片の一部が付着している
穴周辺部では、だれが大きくなる問題がある。
A method for avoiding this problem is the method shown in FIG. However, in this method, since the metal piece 16 is bent and fixed in the pipe, the hole to be formed by piercing does not become a perfect circle, and there is a problem that the part around the hole where a part of the metal piece is attached becomes large. There is.

【0015】図5に示した方法は、製品内に金属片が残
ることはないが、強烈な内圧にて金属片が金型内に押し
出されるため、ダイス内のポンチに金属片が凝着してそ
れを除去する必要が生じる。また、金属片が、飛散して
金型内に残存するので、次の成型時に成形不良が生じる
場合がある。
In the method shown in FIG. 5, no metal piece remains in the product, but the metal piece is extruded into the mold by a strong internal pressure, so that the metal piece adheres to the punch in the die. Need to be removed. In addition, since the metal pieces are scattered and remain in the mold, molding failure may occur during the next molding.

【0016】[0016]

【発明が解決しようとする課題】本発明の課題は、上記
従来の問題を解消し、ピアシング加工により生じる金属
片が製品内に残らず、また金型内にも残すことなくピア
シング加工する方法を提供することにある。
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a method of piercing without leaving a piece of metal generated by piercing in a product and a mold. To provide.

【0017】[0017]

【課題を解決するための手段】本発明の要旨は以下の通
りである。
The gist of the present invention is as follows.

【0018】「一対の金型の一方または双方の内面にダ
イス孔を設け、ダイス孔内に進退可能なポンチをその先
端面が金型内面と同一面を形成するように挿入固定し、
金型内に収納した金属素管に、その内部に導入した加工
液の液圧と金属素管の軸方向圧縮力とを組み合わせて膨
出部を成形し、次いでポンチを後退させてダイス孔に位
置している膨出部を、その内部の液圧によりダイス孔形
状にピアシング加工し、その後ポンチを前進させてピア
シング加工で生じた金属片を押し戻してピアシングによ
り成形した穴にはめ込み、成形品を液圧バルジ加工装置
から取り出した後、穴にはめ込んだ金属片を取り除く金
属管の液圧バルジ加工時のピアシング加工方法」本発明
者らは、上記課題を解消すべく種々実験、検討した結
果、液圧バルジ加工時の内圧を利用して金型内面に設け
たダイスにてピアシング加工し、それにより生じた金属
片はピアシング加工で成形した穴よりも若干大きくなる
ことを知り、この金属片をポンチで押し戻してピアシン
グ加工により成形した穴にはめ直し、その状態で製品を
液圧バルジ加工装置から取り出してから金属片を除去す
ればよいとの知見を得たのである。
A die hole is provided in one or both inner surfaces of a pair of molds, and a punch that can be advanced and retracted in the die hole is inserted and fixed so that the tip surface forms the same surface as the mold inner surface,
The bulged part is formed by combining the hydraulic pressure of the working fluid introduced into the metal tube and the axial compression force of the metal tube into the metal tube housed in the mold, and then the punch is retracted to form the die hole. The bulging portion is pierced into a die hole shape by the internal liquid pressure, then the punch is advanced, the metal piece generated by the piercing process is pushed back, and the pierced portion is fitted into the hole formed by piercing, and the molded product is formed. After being removed from the hydraulic bulging device, the piercing method at the time of hydraulic bulging of the metal tube to remove the metal pieces fitted into the holes '' The present inventors have conducted various experiments and studies to solve the above problems, Utilizing the internal pressure during hydraulic bulging, piercing was performed with a die provided on the inner surface of the mold, and the resulting metal piece was found to be slightly larger than the hole formed by piercing. Reseat the holes were formed by piercing pushes back the piece in the punch, it was obtained a finding from taking out the product from the hydraulic bulging device in that state and may be removed metal pieces.

【0019】[0019]

【発明の実施の形態】本発明の方法は、図1に示すよう
な液圧バルジ加工装置により実施できる。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention can be implemented by a hydraulic bulging machine as shown in FIG.

【0020】図6は、本発明の液圧バルジ加工時のピア
シング方法を説明するための金型部または成形品の断面
図で、図6(a)は液圧バルジ加工が完了した状態、図
6(b)はピアシング加工後の状態、図6(c)は金属
片をピアシング加工により成形した穴にはめん込んだ状
態をそれぞれ示し、図6(d)は金型から取り出した成
形品の状態、図6(e)は金属片を除去した成形品を示
す。
FIG. 6 is a cross-sectional view of a mold or a molded product for explaining a piercing method at the time of hydraulic bulging according to the present invention. FIG. 6 (a) shows a state where hydraulic bulging is completed. 6 (b) shows a state after the piercing, FIG. 6 (c) shows a state where the metal piece is embedded in the hole formed by the piercing, and FIG. 6 (d) shows a state of the molded article taken out from the mold. FIG. 6E shows the molded product from which the metal pieces have been removed.

【0021】図6では、ダイス14を上金型に設けてい
るが、金型自体が硬質であるため特にダイスを新たに設
けなくとも、金型にダイス孔を直接設けることによりダ
イスの機能を発揮させることができる。しかし、摩耗に
よりダイス孔が変形した場合は金型を取り替えなければ
ならないので、簡単に取り替えができるダイスを金型に
設けるのが好ましい。なお、図6ではダイスを一個設け
た場合を示すが、製品が必要とする穴の数だけ設ければ
よい。また、当然のことながら下金型にダイスを設けて
もよい。
In FIG. 6, the die 14 is provided in the upper die. However, since the die itself is hard, the function of the die can be achieved by directly providing the die hole without newly providing a die. Can be demonstrated. However, when the die hole is deformed due to abrasion, the die must be replaced. Therefore, it is preferable to provide a die that can be easily replaced in the die. Although FIG. 6 shows a case where one die is provided, it is sufficient to provide as many holes as required by the product. In addition, a die may be provided in the lower mold as a matter of course.

【0022】図6(a)は、下金型8と上金型7間で金
属素管が、内圧と軸方向の圧縮力との組み合わせによる
液圧バルジ加工により膨出部18が成形された状態を示
し、液圧バルジ加工方法は、前述した従来の方法と同じ
である。
FIG. 6 (a) shows that the metal tube is formed between the lower die 8 and the upper die 7 by a hydraulic bulging process using a combination of an internal pressure and an axial compressive force. The state is shown, and the hydraulic bulging method is the same as the conventional method described above.

【0023】液圧バルジ加工する際、ポンチ12はその
先端がダイスの内面と同じ面を形成する位置に固定して
おこなう。すなわち、図6(a)に示すポンチの位置と
同じ状態としておく。それは、金属管を膨出加工する際
にダイス内に空隙があると、金属管が金型形状通りに膨
張変形する前に、ダイス部で金属管に穴があき、金属管
の膨張と共に穴形状も変形し目的の形状にならないため
である。金属管が金型形状に膨出加工されるまでダイス
穴に栓をする意味でポンチを存在させるのである。
When performing hydraulic bulging, the punch 12 is fixed at a position where the tip forms the same surface as the inner surface of the die. That is, the position is set to be the same as the position of the punch shown in FIG. If there is a gap in the die when expanding the metal tube, before the metal tube expands and deforms according to the mold shape, a hole is made in the metal tube at the die, and the hole shape is expanded with the expansion of the metal tube. Is also deformed and does not have the desired shape. The punch exists in the sense of plugging the die hole until the metal tube is bulged into a mold shape.

【0024】ポンチはポンチ後方のシリンダ等によって
保持されている。シリンダの荷重Fは、液圧バルジ加工
中にポンチが押し戻されないように下記の条件を満たす
ようにすればよい。
The punch is held by a cylinder or the like behind the punch. The load F of the cylinder may satisfy the following conditions so that the punch is not pushed back during hydraulic bulging.

【0025】F>A・Pmax ここで、Pmax:バルジ成形での最大内圧 A :ポンチの断面積(穴の面積) 液圧バルジ加工により膨出部の成形が終了すると、内圧
とダイスによりピアシング加工をおこなう。ピアシング
加工は、図6(b)に示すようにダイス14内のポンチ1
2を上金型7の外方向に後退させてダイス内に空間を生
じさせて内圧により金属管にピアシング加工を施し、膨
出部18に穴をあける加工である。
F> A · Pmax Here, Pmax: maximum internal pressure in bulge forming A: cross-sectional area of punch (area of hole) When forming of the bulging portion by hydraulic bulging is completed, piercing by internal pressure and die Perform As shown in FIG. 6B, the piercing process is performed by using a punch 1 in a die 14.
2 is retracted outward from the upper mold 7 to create a space in the die, piercing the metal tube by internal pressure, and making a hole in the bulging portion 18.

【0026】金属管内の内圧を利用してピアシング加工
をおこなうためには、ピアシング時の内圧pは金属管を
膨張させるに必要な圧力であると共に、金属管にせん断
加工を施すための下記の条件を満たすようにすればよ
い。
In order to perform the piercing process using the internal pressure in the metal pipe, the internal pressure p at the time of piercing is a pressure necessary for expanding the metal pipe, and the following conditions for performing the shearing processing on the metal pipe. Should be satisfied.

【0027】 p> stk/A =4tk/D(丸ポンチの場合) ここで、 s:穴周長 A:穴面積 t:ピアシング部の肉厚 k:せん断抵抗 D:ポンチ径 上記条件を満たした内圧にしておき、ダイス内のポンチ
を後退させることで、膨出部はダイス形状にピアシング
される。ポンチ後退時にダイスと接触している膨出部は
ダイス内で膨らんだ後、ダイスエッジでせん断されるた
め、ポンチの後退ストロークは肉厚の2倍以上にすれば
よい。なお、ダイス孔の形状は製品に必要とされる形状
にしておけばよい。
P> stk / A = 4tk / D (in the case of a round punch) where: s: hole circumference A: hole area t: wall thickness of the piercing part k: shear resistance D: punch diameter The above conditions were satisfied. By setting the internal pressure and retracting the punch in the die, the bulging portion is pierced into a die shape. When the punch is retracted, the bulging portion in contact with the die expands in the die and is then sheared at the die edge. Therefore, the retracting stroke of the punch may be at least twice the wall thickness. Note that the shape of the die hole may be a shape required for the product.

【0028】ピアシング加工が終了すると、図6(c)
に示すように、ポンチ12を前進させて液圧バルジ加工
前の位置に戻すことによりピアシングにより生じた金属
片16を押し戻して穴にはめ込む。金属片は、ピアシン
グ時に湾曲した状態で押し抜かれ、押し抜かれた後はス
プリングバックにより元の状態に戻るためピアシングに
より形成した穴より若干大きくなるため、金属片は穴か
ら簡単に外れることはない。また、金属片がポンチの先
端に凝着したとしても、金属片は穴に強固にはめ込まれ
るため、ポンチを後退させることによりポンチは金属片
から容易に離脱する。
When the piercing process is completed, FIG.
As shown in (2), the punch 12 is advanced and returned to the position before the hydraulic bulging, whereby the metal piece 16 generated by the piercing is pushed back and fitted into the hole. The metal piece is pushed out in a curved state at the time of piercing, and after being pushed out, returns to the original state by springback, so that the metal piece is slightly larger than the hole formed by piercing, so that the metal piece does not easily come off from the hole. Even if the metal piece adheres to the tip of the punch, the metal piece is firmly fitted into the hole, so that the punch is easily separated from the metal piece by retracting the punch.

【0029】次いで、この金属片を付けた液圧バルジ成
形品を金型外に搬送する。図6(d)は金型から取り出
した成形品の縦断面図である。金属片を液圧バルジ成形
品から取り外して、図6(e)に示す製品が得られる。
このようにすることにより、金属管内に金属片が残るこ
とも、金型内に金属片が残存することもない。液圧バル
ジ成形品から金属片を取り出すのは、バキュームにより
金属片を吸着除去するか電磁石等で除去すればよい。
Next, the hydraulic bulge formed with the metal pieces is conveyed out of the mold. FIG. 6D is a longitudinal sectional view of a molded product taken out of the mold. The metal piece is removed from the hydraulic bulge, and the product shown in FIG. 6 (e) is obtained.
By doing so, neither the metal pieces remain in the metal tube nor the metal pieces remain in the mold. The metal pieces may be removed from the hydraulic bulge by vacuum suction or by using an electromagnet or the like.

【0030】ピアシング加工に用いるポンチは、ダイス
内で油圧により前後進させるには、シリンダ及びシリン
ダ作動用の配管を金型内に配置する必要がある。しか
し、通常は液圧バルジ加工用プレス装置の金型のスペー
スは限定されており、油圧装置の設置が困難な場合があ
る。そのような場合には、シリンダー内に油の代わりに
コイルバネやガスのようなクッションに予荷重を付加し
て挿入して置けばよい。
In order to move the punch used for piercing forward and backward in the die by hydraulic pressure, it is necessary to arrange a cylinder and a pipe for operating the cylinder in a die. However, the space of the mold of the press device for hydraulic bulging is usually limited, and it may be difficult to install the hydraulic device. In such a case, a preload may be applied to a cushion such as a coil spring or gas instead of oil and inserted into the cylinder.

【0031】金属素管の液圧バルジ加工時に途中でポン
チが後退移動しないために必要なクッションの初期荷重
F0は、下記式で表せる。
The initial load F0 of the cushion required to prevent the punch from moving backward during the hydraulic bulging of the metal tube can be expressed by the following equation.

【0032】F0 ≧ PE・A ここで、PE:金属管が金型形状に膨張するに必要な内
圧 A:ポンチの断面積 金属素管が金型形状に膨張変形した後、さらに内圧を△
P増加させると、ポンチは後方にδだけ後退する。この
とき、必要な内圧の増加量△Pは下記式で表せる。
F0 ≧ PE · A Here, PE: internal pressure required for the metal tube to expand into the mold shape A: cross-sectional area of the punch After the metal tube expands and deforms into the mold shape, the internal pressure is further increased by △
When P is increased, the punch moves backward by δ. At this time, the required increase amount ΔP of the internal pressure can be expressed by the following equation.

【0033】 △P≧(F0-PE・A)/A + K・δ/A + k・s・t/A ここで、 K:弾性体のバネ定数 この式で、右辺第一項は初期荷重の過剰分、第二項は弾
性体を押し戻すのに必要な荷重、第三項は金属管をせん
断するに必要な荷重を意味する。また、ポンチの移動量
δは金属管がピアシングされるためには、肉厚の2倍以
上が必要となる。
ΔP ≧ (F0−PE · A) / A + K · δ / A + ks · t / A where K: spring constant of elastic body In this equation, the first term on the right side is the initial load. The second term means the load required to push back the elastic body, and the third term means the load required to shear the metal pipe. In addition, the amount of movement δ of the punch needs to be at least twice the wall thickness in order for the metal tube to be pierced.

【0034】金属素管の膨出成形およびピアシング加工
の終了後、内圧を下げると内圧によって後退していたポ
ンチが初期位置まで移動する。そのとき、金属片はピア
シングにより成形した穴に押し戻されることとなる。こ
のように油圧の代わりにクッションを用いることにより
装置がコンパクト化される。
After the completion of the bulging and piercing of the metal tube, when the internal pressure is reduced, the punch that has been retracted by the internal pressure moves to the initial position. At that time, the metal piece is pushed back into the hole formed by piercing. The use of the cushion instead of the hydraulic pressure makes the device compact.

【0035】[0035]

【実施例】金属素管として、外径:60.5mm、肉
厚:2mm、長さ:800mmの機械構造用炭素鋼管S
TKM11A (JISG3445)を用いた。この鋼管の降伏強さ
は33kg/mm2、引張強さは40kg/mm2であっ
た。この素管を、図1および図2に示した液圧バルジ加
工装置により図7に示す形状の異形管を成形した後、ピ
アシングをおこなった。成形後の異形管の寸法は下記の
通りであった。
EXAMPLE A carbon steel pipe S for machine structure having an outer diameter of 60.5 mm, a wall thickness of 2 mm and a length of 800 mm as a metal element tube.
TKM11A (JISG3445) was used. The yield strength of this steel pipe was 33 kg / mm 2 , and the tensile strength was 40 kg / mm 2 . A pipe having the shape shown in FIG. 7 was formed from the raw pipe by the hydraulic bulging apparatus shown in FIGS. 1 and 2 and then pierced. The dimensions of the deformed tube after molding were as follows.

【0036】高さ H(mm) 46 mm 幅 W(mm) 75 mm 長さ L(mm) 760 mm 端部外径 D(mm) 60.5 mm 図8は、液圧バルジ成形時の内圧−軸押し量のパターン
を示す図である。図8中のAの時点でピアシング加工を
おこなった。使用したポンチの外径は18mmで、ポン
チの後退量は6mmとした。また、ポンチを支える油圧
シリンダの初期荷重は3トンとし、ピアシング加工後、
金属片を穴に押し戻す際も荷重3tonとした。ピアシン
グ加工した後、金型から成形品を取り出して電磁石で金
属片を除去した。
Height H (mm) 46 mm Width W (mm) 75 mm Length L (mm) 760 mm Outer end diameter D (mm) 60.5 mm FIG. 8 shows internal pressure-axial pressing during hydraulic bulge molding. FIG. 4 is a diagram showing a pattern of an amount. Piercing was performed at the point A in FIG. The outer diameter of the punch used was 18 mm, and the retreat amount of the punch was 6 mm. The initial load of the hydraulic cylinder supporting the punch is 3 tons, and after piercing,
The load was also 3 tons when pushing the metal piece back into the hole. After piercing, the molded product was taken out of the mold and the metal pieces were removed with an electromagnet.

【0037】従来例として、上記と同じ条件で液圧バル
ジ加工をおこなった後、図3に示したピアシング加工を
おこなった。ピアシング条件も上記と同じとした。
As a conventional example, after performing hydraulic bulge processing under the same conditions as described above, piercing processing shown in FIG. 3 was performed. The piercing conditions were the same as above.

【0038】液圧バルジ加工−ピアシング加工を各10
0回おこない、金属片の状態を調べた。
Hydraulic bulging-piercing 10 times each
The test was performed 0 times, and the state of the metal piece was examined.

【0039】本発明例では、金属片は全て成形品外に除
去できたが、従来例ではピアシングにより生じた金属片
の5%がピアシングにより成形した穴に一部付着した状
態となり、それ以外は全て成型品内に残った。
In the example of the present invention, all of the metal pieces could be removed outside the molded product. However, in the conventional example, 5% of the metal pieces generated by piercing were partially adhered to the holes formed by piercing. All remained in the molded product.

【0040】[0040]

【発明の効果】本発明の方法によれば、、ピアシング時
の金属片が成形品内に残存したり、金型内に飛散、残存
することなく、金属片を容易に除去でき、生産効率が向
上する。
According to the method of the present invention, the metal pieces can be easily removed without causing the metal pieces at the time of piercing to remain in the molded product, or to scatter and remain in the mold, and the production efficiency can be reduced. improves.

【図面の簡単な説明】[Brief description of the drawings]

【図1】金属管の液圧バルジ加工およびピアシング加工
装置を示す図である。
FIG. 1 is a view showing an apparatus for hydraulic bulging and piercing of a metal tube.

【図2】図1の金型部の拡大断面図である。FIG. 2 is an enlarged sectional view of a mold part of FIG.

【図3】従来のピアシング方法を説明するための図であ
る。
FIG. 3 is a diagram for explaining a conventional piercing method.

【図4】従来のピアシング方法を説明するための図であ
る。
FIG. 4 is a diagram for explaining a conventional piercing method.

【図5】従来のピアシング方法を説明するための図であ
る。
FIG. 5 is a diagram for explaining a conventional piercing method.

【図6】本発明におけるピアシング方法を説明するため
の図である。
FIG. 6 is a diagram illustrating a piercing method according to the present invention.

【図7】実施例で成形した製品の縦断面図である。FIG. 7 is a longitudinal sectional view of a product formed in the example.

【図8】バルジ加工時の内圧、軸押し量のパターンの説
明図である。
FIG. 8 is an explanatory diagram of a pattern of an internal pressure and an axial pressing amount during bulging.

【符号の簡単な説明】[Brief description of reference numerals]

1 ベッド 10 シール工具 2 クラウン 11a、11b ダイス
内面 3 コラム 12 ポンチ 4 油圧シリンダー 13 油圧シリンダー 5 ピストン 17 ダイス孔 7 上金型 20 加工液導入孔 8 下金型 9 軸押し装置
1 Bed 10 Sealing tool 2 Crown 11a, 11b Die inner surface 3 Column 12 Punch 4 Hydraulic cylinder 13 Hydraulic cylinder 5 Piston 17 Dice hole 7 Upper die 20 Working fluid introduction hole 8 Lower die 9 Axial pressing device

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】一対の金型の一方または双方の内面にダイ
ス孔を設け、ダイス孔内に進退可能なポンチをその先端
面が金型内面と同一面を形成するように挿入固定し、金
型内に収納した金属素管に、その内部に導入した加工液
の液圧と金属素管の軸方向圧縮力とを組み合わせて膨出
部を成形し、次いでポンチを後退させてダイス孔に位置
している膨出部を、その内部の液圧によりダイス孔形状
にピアシング加工し、その後ポンチを前進させてピアシ
ング加工で生じた金属片を押し戻してピアシングにより
成形した穴にはめ込み、成形品を液圧バルジ加工装置か
ら取り出した後、穴にはめ込んだ金属片を取り除くこと
を特徴とする金属管の液圧バルジ加工時のピアシング加
工方法。
1. A die hole is provided in one or both inner surfaces of a pair of dies, and a punch which can be advanced and retracted in the die hole is fixed so that the tip surface thereof is flush with the inner surface of the die. The metal tube accommodated in the mold is combined with the hydraulic pressure of the working fluid introduced therein and the axial compression force of the metal tube to form a bulge, and then the punch is retracted to position the metal tube in the die hole. The bulging part is pierced into a die hole shape by the internal liquid pressure, and then the punch is advanced, the metal piece generated by the piercing processing is pushed back, fitted into the hole formed by piercing, and the molded product is subjected to liquid piercing. A piercing method at the time of hydraulic bulging of a metal pipe, wherein a metal piece fitted into a hole is removed after being taken out of a pressure bulging device.
JP19358699A 1999-07-07 1999-07-07 Piercing method for hydraulic bulge processing of metal pipes Expired - Fee Related JP3674393B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP19358699A JP3674393B2 (en) 1999-07-07 1999-07-07 Piercing method for hydraulic bulge processing of metal pipes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19358699A JP3674393B2 (en) 1999-07-07 1999-07-07 Piercing method for hydraulic bulge processing of metal pipes

Publications (2)

Publication Number Publication Date
JP2001018016A true JP2001018016A (en) 2001-01-23
JP3674393B2 JP3674393B2 (en) 2005-07-20

Family

ID=16310452

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP3674393B2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1719564A1 (en) * 2004-02-20 2006-11-08 Sumitomo Metal Industries, Ltd. Hydroformed part, hydroforming method, and mold used for the hydroforming method
JP2006336490A (en) * 2005-05-31 2006-12-14 Usui Kokusai Sangyo Kaisha Ltd Fuel delivery pipe and manufacturing method of fuel delivery pipe
JP2013500866A (en) * 2009-08-05 2013-01-10 ジ.ディ.メカニカ ソチエタ ペル アチオニ Method for obtaining an opening in a hollow body member, and hollow body member with one or more openings obtained by this method
CN107262584A (en) * 2017-08-08 2017-10-20 天津天锻航空科技有限公司 A kind of customized parameter sheet material bulging assembling die and bulging experimental method
KR102567878B1 (en) * 2022-10-04 2023-08-16 윤영태 Hydroforming molding device for EGR cooler housing molding

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1719564A1 (en) * 2004-02-20 2006-11-08 Sumitomo Metal Industries, Ltd. Hydroformed part, hydroforming method, and mold used for the hydroforming method
US7464571B2 (en) 2004-02-20 2008-12-16 Sumito Metal Industries, Ltd. Hydroforming method and mold used for the hydroforming method
EP1719564A4 (en) * 2004-02-20 2010-02-03 Sumitomo Metal Ind Hydroformed part, hydroforming method, and mold used for the hydroforming method
JP2006336490A (en) * 2005-05-31 2006-12-14 Usui Kokusai Sangyo Kaisha Ltd Fuel delivery pipe and manufacturing method of fuel delivery pipe
JP4488517B2 (en) * 2005-05-31 2010-06-23 臼井国際産業株式会社 Fuel delivery pipe and method for manufacturing the same
JP2013500866A (en) * 2009-08-05 2013-01-10 ジ.ディ.メカニカ ソチエタ ペル アチオニ Method for obtaining an opening in a hollow body member, and hollow body member with one or more openings obtained by this method
CN107262584A (en) * 2017-08-08 2017-10-20 天津天锻航空科技有限公司 A kind of customized parameter sheet material bulging assembling die and bulging experimental method
CN107262584B (en) * 2017-08-08 2023-07-28 天津天锻航空科技有限公司 Board bulging combined die with adjustable parameters and bulging experimental method
KR102567878B1 (en) * 2022-10-04 2023-08-16 윤영태 Hydroforming molding device for EGR cooler housing molding

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