JP3437404B2 - Manufacturing method of bifurcated forgings - Google Patents

Manufacturing method of bifurcated forgings

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Publication number
JP3437404B2
JP3437404B2 JP9806997A JP9806997A JP3437404B2 JP 3437404 B2 JP3437404 B2 JP 3437404B2 JP 9806997 A JP9806997 A JP 9806997A JP 9806997 A JP9806997 A JP 9806997A JP 3437404 B2 JP3437404 B2 JP 3437404B2
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JP
Japan
Prior art keywords
mold
forging
forged
split plate
webs
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.)
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JP9806997A
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Japanese (ja)
Other versions
JPH10277693A (en
Inventor
悦夫 村井
信市 小野
忠温 桃野
聖司 高田
Original Assignee
株式会社日本製鋼所
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Application filed by 株式会社日本製鋼所 filed Critical 株式会社日本製鋼所
Priority to JP9806997A priority Critical patent/JP3437404B2/en
Publication of JPH10277693A publication Critical patent/JPH10277693A/en
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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21KMAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
    • B21K1/00Making machine elements
    • B21K1/06Making machine elements axles or shafts
    • B21K1/08Making machine elements axles or shafts crankshafts

Description

【発明の詳細な説明】 【0001】 【発明の属する技術分野】本発明は、半組立式クランク
シャフトに用いられるクランクスロー等の二股形状鍛造
品の製造方法に関するものである。 【0002】 【従来の技術】船舶等の大型ディーゼル機関に用いられ
るクランクシャフトの製造方法に、クランクアームとピ
ンとが形成されたクランクスローとジャーナルとを別々
に製造し、これらを焼きばめ等によって一体化する半組
立式法がある。この方法に用いられるクランクスロー
は、2つのアームと両アーム間に形成されたピンとによ
り構成されており、各種の鍛造方法により製造されてい
る。その一つとして折曲げ鍛造法があり、この方法で
は、図4に示すように両端を扁平にした荒地材20を中
央で折り曲げ、その後、上型21,下型22を用いて、
ウェブ20a、ピン部20bを鍛錬成形する。また他の
方法として、密閉型を用いた型入れ鍛造法があり、この
方法では図5に示すように密閉型30内に素材31全体
を納め、上方から割り板32を圧入して、押出し状に2
つのアーム31a、31aを形成するとともに、割り板
32の先端面でピン部31bを絞り込んで形成するもの
である。 【0003】 【発明が解決しようとする課題】しかし、従来の方法の
うち前者では、自由鍛造により加工が行われるため、ウ
ェブ長さのくい違い等により、歩留が悪いという問題が
ある。また、荒地材の製造工程およびその後の工程が複
雑であり、製造に手間がかかるという問題もある。一
方、後者の従来方法では、密閉型内で一気に鍛造が行わ
れるため、簡単な工程により製造することができ、また
十分な鍛錬効果が得られるという利点を有している。し
かし、割り板の圧入に際し高加圧力が必要になるためプ
レス装置への負担が大きく大容量のプレスが必要にな
り、金型製作費を含めた設備費が嵩むという問題があ
る。しかも鍛造品の寸法によっては鍛造自体が困難にな
るため、鍛造品の寸法がプレス装置の能力によって制約
されるという問題がある。本発明は、上記事情を背景と
してなされたものであり、必要な加圧力が軽減されると
ともに所望の鍛錬効果が十分に得られ、低コストで高品
質の鍛造品が得られる製造方法を提供することを目的と
する。 【0004】 【課題を解決するための手段】上記課題を解決するため
本発明の二股形状鍛造品の製造方法のうち第1の発明
は、相対する二つのウェブと両ウェブの一端部間に形成
された連結部とからなる二股形状鍛造品の製造方法にお
いて、該鍛造品に加工される塊状の素材を前記連結部が
形成される素材端部側のみが型穴内に収まるように浅い
型穴形状の型に設置した後、据え込み鍛造し、その後、
素材の他端側から素材に割り板を圧入して素材の一方側
を分断するとともに、割り板の先端面による絞り込みに
よって型穴内に収まっている素材の端部側に連結部を形
成し、さらに上記各分断片をそれぞれ鍛伸して二つのウ
ェブを形成するとともに、前記型の開放面の高さ位置
が、連結部絞り込み面の最高さ位置を基準にして、該位
置における連結部の高さ方向の肉厚をtとして、−0.
6t〜0.6tの範囲内にあることを特徴とする 【0005】 【0006】 【0007】本発明で製造対象となる鍛造品としては、
前述したように、大型材でピン部に相当の負荷がかかる
クランクスローが好適である。この場合、2つのウェブ
がクランクアームに相当する部位になり、連結部がピン
部に相当する部位になる。ただし、本発明としては、そ
の対象が上記クランクスローに限定されるものではな
く、二つのウェブと、両ウェブ間に形成された連結部と
を有する各種の二股形状品に適用することができる。ま
た、鍛造品の細部の形状も特に限定されることはなく、
上記のように2つのウェブとウェブ間の連結部とを有す
るものであれば、細部形状は問わないものである。 【0008】本発明では、塊状の素材を用いて、これを
加工する。塊状の素材は、鋳放しのままでもよく、また
荒地鍛造を施したものでもよく、本発明の鍛造による変
形に合わせた形状、寸法を有している。なお、素材とし
ては通常は、鋼塊が用いられるが、本発明としては、素
材の種別、成分が特に限定されるものではない。本発明
では浅い型穴の型を用い、この型穴に、上記素材のう
ち、連結部が形成される端部側のみを収める。これは、
該端部側は密閉され、その上方は解放された一部密閉型
状態になることを意味している。この型を用いて割り板
を圧入することにより、ウェブ側には大きな鍛錬作用は
与えられないものの比較的小さな加圧力で素材を分断す
ることができ、さらに、小さな加圧力によっても連結部
が形成される素材端部側には割り板と型とによる絞り込
みにより大きな鍛錬作用が与えられる。これは、本発明
者達の研究により、クランクスローのような二股形状品
では、通常は、そのピン部すなわち連結部に負荷応力が
高くかかるため、鍛錬作用もこの部位に集中して得られ
れば特性上問題はないという結論を得たためである。 【0009】上記観点から、型穴に収まる素材の高さ、
すなわち、型の開放面の高さを定めればよい。なお、割
り板の圧入によって形成される連結部は、全てが型穴内
に位置していても良いが、一部のみが型穴内に位置し
て、他部は型穴よりも上方に位置するものであっても良
い。具体的には、型の開放面の高さ位置が、連結部絞り
込み面の最高さ位置を基準にして、該位置における連結
部の高さ方向の肉厚をtとして、−0.6t〜0.6t
の範囲内にあるものとする。これは、型の開放面の高さ
が、上記基準位置よりも0.6tを越えて低いと、連結
部に対し十分な鍛錬作用を与えられないためであり、ま
た、基準位置よりも0.6tを越えて高いと、割り板に
加えるべき加圧力が大きくなって、プレス装置への負担
を軽減するという本発明の目的が十分に達成されないた
めである。なお、同様の理由で、上記開放面高さは、基
準位置から−0.5t〜0.5tの範囲内にあるのが一
層望ましい。 【0010】上記により、一方側で分断され、他端部側
で連結部が形成された素材は、次いで、分断片の鍛伸が
行われる。鍛伸に際しては、上記割り板をそのまま使用
することも可能であるが、上記割り板を取り除き、新た
に鍛伸用の割り板を挿入することもできる。これら割り
板を下型として、分断片外部からの上型の圧下によって
それぞれの分断片を鍛伸してウェブを形成する。上記に
より二つのウェブと、ウェブ間の連結部とを形成した鍛
造品は、必要に応じて、仕上げ鍛造、機削り等の仕上げ
加工や熱処理等を施して製品化する。すなわち、本発明
としては、上記鍛造以降の工程の有無やその内容は問わ
ないものである。 【0011】 【発明の実施の形態】以下に、本発明の一実施形態を図
1〜図3を用いて説明する。所望の組成を有する鋼塊を
荒地鍛造して4角柱形状の素材1とし、一方、この素材
1を設置する型3は、図1に示したように浅い四角形状
の型穴3aを有する筒形状からなる。上記型穴3aは、
下方に至るに連れて寸法が小さくなる形状を有してお
り、その底部中央には、連結部受け板4が突出して底部
の長辺方向に沿って延伸するように形成されている。 【0012】そして、図1に示すように上記の型3に素
材1を設置する際には、互いの長辺方向を合わせて素材
1の下端部側を型穴3aに挿入して収める。さらに以降
の工程を説明すると、素材1を型3に設置した後、据え
込み鍛造を行い、型穴3aに収まっている素材1の下端
部を型穴3aに密着させる。次いで、据え込み鍛造した
素材1aに対し、上部側から割り板5を素材1の頂部に
当てて圧入する。 【0013】上記割り板5を引き続き圧入していくと、
素材1aの上部側は2つに分断されて、分断片10、1
0が形成される。上記割り板5を所定の位置にまで押し
下げると、割り板5の下方側に、割り板5の下面と連結
部受け板4の上面とによって挟まれ、それぞれの面に沿
った形状の連結部10bが形成される。この連結部10
bは、割り板5の圧入によって絞り込みがなされてお
り、大きな鍛錬作用が与えられている。なお、上記割り
板5を最下方位置にまで圧入した際に、型3の開放面
(上表面)3bは、連結部10bの中央高さよりもやや
上方に位置している。 【0014】次いで、型3から素材1aを外し、上記割
り板5に変えて鍛伸用割り板6を分断片10、10間に
配置し、この割り板6を下型として、上型7、7を用い
て、各分断片10、10を鍛伸して所定厚のウェブ10
a、10aを形成する。以上の工程により、二つのウェ
ブ10a、10aと、ウェブ間に形成された連通部10
bとを有する二股形状鍛造品100が得られる。この鍛
造品は、さらに機削りの加工を施して、ウェブ10a、
10aをクランクアーム、連結部10bをクランクピン
部に加工して、製品形状のクランクスローを得る。 【0015】 【実施例】表1に示す成分の炭素鋼を用い、11トンの
容量の素材を用意した。この素材を上記実施形態と同様
の手順により型に設置し、割り板を3000トンプレス
により圧入した。割り板を最終位置にまで圧入した際
に、型の開放面の高さ位置は、連結部の絞り込み面の最
高さ位置を基準にして、該位置における連結部の高さ方
向の肉厚をtとして、−0.4tであった。次いで、上
記実施形態と同様にウェブの鍛伸を行って鍛造品を製造
し、その後、870℃×5時間で加熱後、空冷する焼準
を行い、さらに620℃×20時間で加熱後、炉冷する
焼鈍を行った。これら熱処理を施した鍛造品の連結部の
中央上部側およびウェブから試験片を採取した。 【0016】また、比較のため、上記と同容量の素材を
用いて、10000トン程度の大容量のプレスにより従
来の型入れ鍛造を行い、その後、上記と同様の熱処理を
施した。この鍛造品の連結部からも上記と同位置におい
て試験片を採取した。なお、この型入れ鍛造では、30
00トン程度の容量の小さいプレスでは圧下力不足のた
め鍛造は困難であった。上記より得られた試験片の機械
的特性を測定し、その結果を表2に示した。表2から明
らかなように、本発明法によれば、連結部において顕著
な鍛錬効果が得られており、その効果は、従来の型入鍛
造品と同等のものであった。すなわち、本発明法によれ
ば、小さな圧下力によっても、必要な部位に必要な鍛錬
効果を与えることができる。 【0017】さらに、比較のため、型の開放面の高さを
変えて鍛造試験を行った。すなわち、型の開放面の高さ
位置を、上記基準位置から0.7t高い位置にしたとこ
ろ、必要な圧下力が増大して、3000トン程度の容量
の小さいプレスの装置では鍛造が困難であった。また、
型の開放面の高さ位置を、上記基準位置よりも0.7t
だけ低い位置にしたところ、連結部の上部位置では、降
伏点が374N/mm2、引張強さが642N/mm2
なり、十分な鍛錬作用は得られなかった。 【0018】 【表1】 【0019】 【表2】【0020】 【発明の効果】以上説明したように、本発明の二股形状
鍛造品の製造方法によれば、相対する二つのウェブと両
ウェブの一端部間に形成された連結部とからなる二股形
状鍛造品の製造方法において、該鍛造品に加工される塊
状の素材を前記連結部が形成される素材端部側のみが型
穴内に収まるように浅い型穴形状の型に設置した後、据
え込み鍛造し、その後、素材の他端側から素材に割り板
を圧入して素材の一方側を分断するとともに、割り板の
先端面による絞り込みによって型穴内に収まっている素
材の端部側に連結部を形成し、さらに上記各分断片をそ
れぞれ鍛伸して二つのウェブを形成するとともに、前記
型の開放面の高さ位置が、連結部絞り込み面の最高さ位
置を基準にして、該位置における連結部の高さ方向の肉
厚をtとして、−0.6t〜0.6tの範囲内にある
で、小さな圧下力によっても必要な部位、すなわち大き
な負荷が掛かりやすい連結部に十分な鍛錬作用を与える
ことができ、高品質の鍛造品を小さな容量のプレス装置
で低コストで製造することができる。また、割り板の圧
入による絞り込み効果を連結部に相当する部位に十分か
つ効率的に作用させることができる。さらに、型の開放
面の高さ位置を、連結部絞り込み面の最高さ位置を基準
にして、該位置における連結部の高さ方向の肉厚をtと
して、−0.6t〜0.6tの範囲内にしているので、
必要な圧下力を十分に減少させることができるととも
に、鍛錬作用をより確実に得ることができる。 【0021】 【0022】
Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a forked product such as a crank throw used in a semi-assembled crankshaft. 2. Description of the Related Art In a method of manufacturing a crankshaft used for a large diesel engine such as a ship, a crank throw and a journal having a crank arm and a pin are separately manufactured, and these are shrink-fitted or the like. There is a semi-assembly method to integrate. The crank throw used in this method is constituted by two arms and a pin formed between both arms, and is manufactured by various forging methods. One of the methods is a bending forging method. In this method, as shown in FIG. 4, a rough ground material 20 having both ends flattened is bent at the center, and thereafter, an upper mold 21 and a lower mold 22 are used.
The web 20a and the pin portion 20b are forged. As another method, there is a mold forging method using a closed mold. In this method, as shown in FIG. 5, the entire raw material 31 is placed in a closed mold 30 and a split plate 32 is press-fitted from above and extruded. To 2
The two arms 31a, 31a are formed, and the pin portion 31b is narrowed down at the tip end surface of the split plate 32. [0003] However, in the former method among the conventional methods, since the working is performed by free forging, there is a problem that the yield is poor due to a difference in web length and the like. Further, there is also a problem that the manufacturing process of the waste material and the subsequent process are complicated, and the manufacturing is troublesome. On the other hand, in the latter conventional method, forging is performed at once in a closed mold, so that it can be manufactured by a simple process and has an advantage that a sufficient forging effect can be obtained. However, a high pressing force is required for press-fitting the split plate, which imposes a heavy burden on the press device, requires a large-capacity press, and raises equipment costs including mold manufacturing costs. Moreover, forging itself becomes difficult depending on the size of the forged product, and thus there is a problem that the size of the forged product is limited by the capability of the press device. The present invention has been made in view of the above circumstances, and provides a manufacturing method capable of reducing required pressing force, sufficiently obtaining a desired forging effect, and obtaining a high-quality forged product at low cost. The purpose is to: [0004] In order to solve the above-mentioned problems, a first invention of the method for manufacturing a forked product of the present invention comprises forming two opposed webs and one end between the two webs. A forked product formed of a forked product formed of a forked product, and a massive material to be processed into the forged product is formed into a shallow mold hole shape so that only the material end side on which the connection portion is formed fits in the mold hole. After setting in the mold, upset forging , then
Pressing the split plate into the material from the other end of the material and cutting one side of the material, forming a connecting part on the end side of the material that is contained in the mold hole by narrowing by the tip surface of the split plate, Each of the above-mentioned pieces is forged to form two webs, and the height position of the open surface of the mold
However, the position of the connection
-T.
The forged product to be manufactured according to the present invention is characterized by being within the range of 6 t to 0.6 t .
As described above, a crank throw which is a large-sized material and in which a considerable load is applied to the pin portion is preferable. In this case, the two webs are portions corresponding to the crank arm, and the connecting portion is a portion corresponding to the pin portion. However, the object of the present invention is not limited to the above-mentioned crank throw, but can be applied to various bifurcated articles having two webs and a connecting portion formed between the two webs. Also, the shape of the details of the forged product is not particularly limited,
As long as it has two webs and a connecting portion between the webs as described above, the detailed shape is not limited. In the present invention, a lump-shaped raw material is used and processed. The lump-shaped material may be as-cast, or may be subjected to rough-land forging, and has a shape and dimensions according to the deformation by forging of the present invention. In addition, although a steel ingot is usually used as a raw material, in the present invention, the type and composition of the raw material are not particularly limited. In the present invention, a mold having a shallow mold hole is used, and only the end portion side of the above-mentioned material where the connecting portion is formed is placed in the mold hole. this is,
This means that the end side is closed, and the upper part thereof is in an open and partially closed state. By press-fitting the split plate using this mold, the material can be separated with a relatively small pressing force, although a large forging action is not given to the web side, and the connection part is formed even with a small pressing force A large forging action is given to the end portion of the material to be formed by narrowing by the split plate and the mold. According to the study of the present inventors, in the case of a forked product such as a crank throw, a high load stress is usually applied to the pin portion, that is, the connecting portion. This is because it was concluded that there was no problem in characteristics. In view of the above, the height of the material that fits in the mold cavity,
That is, the height of the open surface of the mold may be determined. In addition, the connecting portion formed by press-fitting the split plate may be entirely located in the mold hole, but only a part is located in the mold hole, and the other portion is located above the mold hole. It may be. Specifically, the height position of the opening surface of the mold is -0.6t to 0, where t is the thickness of the connecting portion at the position in the height direction with respect to the highest position of the connecting portion narrowing surface. .6t
It is intended to be within the scope of. This is because if the height of the open surface of the mold is lower than the reference position by more than 0.6 t, sufficient forging action cannot be given to the connecting portion. If it is higher than 6t, the pressing force to be applied to the split plate becomes large, and the object of the present invention of reducing the load on the press device is not sufficiently achieved. For the same reason, the height of the open surface is more preferably in the range of -0.5t to 0.5t from the reference position. [0010] As described above, the raw material that has been cut off on one side and has a connecting portion formed on the other end is then forged and drawn into divided pieces. When forging / stretching, it is possible to use the split plate as it is, but it is also possible to remove the split plate and insert a new split plate for forging. These split plates are used as lower dies, and the respective split pieces are forged and stretched by pressing down the upper die from the outside of the split pieces to form a web. The forged product in which the two webs and the connecting portion between the webs are formed as described above is subjected to finish working such as finish forging and machine cutting, heat treatment, and the like, as necessary, to produce a product. That is, the present invention does not matter whether or not there is a step after the forging and the content thereof. An embodiment of the present invention will be described below with reference to FIGS. A steel ingot having a desired composition is forged in rough ground to form a quadrangular prism-shaped material 1. On the other hand, a mold 3 for installing the material 1 has a cylindrical shape having a shallow square-shaped mold hole 3a as shown in FIG. Consists of The mold cavity 3a is
The connection portion receiving plate 4 is formed at the center of the bottom so as to protrude and extend along the long side direction of the bottom portion. As shown in FIG. 1, when the blank 1 is placed in the mold 3, the lower end of the blank 1 is inserted into the mold hole 3a so as to match the long sides thereof. To explain the subsequent steps, after setting the blank 1 in the mold 3, upsetting forging is performed, and the lower end of the blank 1 accommodated in the mold hole 3a is brought into close contact with the mold hole 3a. Next, the split plate 5 is pressed against the top of the blank 1 from the upper side with respect to the upset and forged blank 1a. When the above-mentioned split plate 5 is continuously press-fitted,
The upper side of the material 1a is divided into two, and the divided pieces 10, 1
0 is formed. When the split plate 5 is pushed down to a predetermined position, the lower surface of the split plate 5 is sandwiched between the lower surface of the split plate 5 and the upper surface of the connecting portion receiving plate 4 to form a connecting portion 10b along the respective surfaces. Is formed. This connecting part 10
b is narrowed down by press-fitting of the split plate 5, and a large forging action is given. When the split plate 5 is pressed into the lowermost position, the open surface (upper surface) 3b of the mold 3 is located slightly above the center height of the connecting portion 10b. Next, the blank 1a is removed from the mold 3, and the forging / splitting plate 6 is disposed between the split pieces 10 and 10 in place of the above-mentioned split plate 5, and the split plate 6 is used as a lower die, and the upper die 7 and Each of the pieces 10, 10 is forged using the web 7 to form a web 10 having a predetermined thickness.
a and 10a are formed. By the above steps, the two webs 10a, 10a and the communication portion 10 formed between the webs
b) and the forked product 100 having the forked shape having the shape b is obtained. This forged product is further machined to produce a web 10a,
The crankshaft 10a is processed into a crank arm, and the connecting portion 10b is processed into a crankpin portion to obtain a product-shaped crank throw. EXAMPLE A material having a capacity of 11 tons was prepared using carbon steel having the components shown in Table 1. This material was placed in a mold in the same manner as in the above embodiment, and the split plate was pressed in with a 3000-ton press. When the split plate is press-fitted to the final position, the height position of the open surface of the mold is based on the highest position of the narrowing surface of the connection portion, and the thickness of the connection portion at that position in the height direction is t. Was -0.4t. Next, forging is performed by forging the web in the same manner as in the above embodiment, and then heating is performed at 870 ° C. × 5 hours, air-cooled, and further heated at 620 ° C. × 20 hours. Annealing to cool was performed. Specimens were taken from the upper central part of the joint and the web of the heat-treated forged product. For comparison, a conventional mold forging was performed by using a material having the same capacity as described above and using a large-capacity press of about 10,000 tons, and then subjected to the same heat treatment as described above. A test piece was also taken from the joint of this forged product at the same position as above. In addition, in this mold forging, 30
Forging with a small press of about 00 tons was difficult due to insufficient rolling force. The mechanical properties of the test pieces obtained as described above were measured, and the results are shown in Table 2. As is clear from Table 2, according to the method of the present invention, a remarkable forging effect was obtained at the connection portion, and the effect was equivalent to that of the conventional die-forged product. That is, according to the method of the present invention, a necessary training effect can be given to a required portion even with a small rolling force. Further, for comparison, a forging test was performed while changing the height of the open surface of the mold. That is, when the height position of the open surface of the mold is set at a position 0.7 ton higher than the reference position, the required rolling force increases, and it is difficult to forge with a press machine having a small capacity of about 3000 tons. Was. Also,
The height position of the open surface of the mold should be 0.7 t above the reference position.
However, at the lower position, the yield point was 374 N / mm 2 and the tensile strength was 642 N / mm 2 at the upper position of the connecting portion, and a sufficient forging action could not be obtained. [Table 1] [Table 2] As described above, according to the method for manufacturing a forked product of the present invention, the forked product comprises two opposing webs and a connecting portion formed between one end of both webs. the method of manufacturing a shape forgings, after setting the type of shallow mold cavity shaped so that only the material end side of the connecting portion material of the bulk to be processed into forged article is formed is within a mold cavity,据
Inset forging , then press-fit the split plate from the other end of the material into the material to cut one side of the material, and narrow it down by the leading end surface of the split plate to the end of the material that fits in the mold hole. Forming a connecting portion, further forging each of the above-mentioned pieces to form two webs ,
The height of the open surface of the mold is the highest of the narrowing surface of the connecting part
With respect to the position, the thickness of the connecting portion at the position in the height direction
Assuming that the thickness is in the range of -0.6t to 0.6t , a sufficient forging action is given to a portion required even by a small rolling force, that is, a connection portion where a large load is likely to be applied. And high quality forgings can be produced at low cost with a small capacity press machine. Also, the split plate pressure
Is the effect of narrowing down due to the insertion sufficient for the part corresponding to the connection part?
And it can work efficiently. In addition, opening the mold
The height position of the surface is based on the highest position of the connection part narrowing surface
And the thickness in the height direction of the connecting portion at the position is t.
Then, since it is in the range of -0.6t to 0.6t,
The required rolling force can be reduced sufficiently
In addition, the training action can be obtained more reliably. [0021]
【図面の簡単な説明】 【図1】 本発明の一実施形態における製造工程の一部
を示す工程図である。 【図2】 同じく製造工程の一部を示す工程図である。 【図3】 同じく得られた鍛造品の正面図である。 【図4】 従来の折曲げ鍛造法の工程図である。 【図5】 同じく型入れ鍛造法の工程図である。 【符号の説明】 1 素材 1a 素材 3 型 3a 型穴 4 連結部受け板 5 割り板 6 鍛伸用割り板 7 上型 10 分断片 10a ウェブ 10b 連結部 100 二股形状鍛造品
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process chart showing a part of a manufacturing process in one embodiment of the present invention. FIG. 2 is a process drawing showing part of the manufacturing process. FIG. 3 is a front view of the forged product obtained in the same manner. FIG. 4 is a process diagram of a conventional bending forging method. FIG. 5 is a process chart of the mold forging method. [Description of Signs] 1 Material 1a Material 3 Mold 3a Mold hole 4 Connecting part receiving plate 5 Split plate 6 Forging / spreading plate 7 Upper die 10-minute piece 10a Web 10b Connecting part 100 Bifurcated forged product
───────────────────────────────────────────────────── フロントページの続き (72)発明者 高田 聖司 北海道室蘭市茶津町4番地 株式会社日 本製鋼所内 (56)参考文献 特開 平6−179035(JP,A) 特開 昭60−223634(JP,A) 特開 平6−575(JP,A) 特開 昭61−27136(JP,A) (58)調査した分野(Int.Cl.7,DB名) B21J 1/00 - 13/14 B21J 17/00 - 19/04 B21K 1/00 - 31/00 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Seiji Takada 4 Chazu-cho, Muroran-shi, Hokkaido Japan Steel Works, Ltd. (56) References JP-A-6-179035 (JP, A) JP-A-60-223634 ( JP, A) JP-A-6-575 (JP, A) JP-A-61-27136 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) B21J 1/00-13/14 B21J 17/00-19/04 B21K 1/00-31/00

Claims (1)

  1. (57)【特許請求の範囲】 【請求項1】 相対する二つのウェブと両ウェブの一端
    部間に形成された連結部とからなる二股形状鍛造品の製
    造方法において、該鍛造品に加工される塊状の素材を前
    記連結部が形成される素材端部側のみが型穴内に収まる
    ように浅い型穴形状の型に設置した後、据え込み鍛造
    、その後、素材の他端側から素材に割り板を圧入して
    素材の一方側を分断するとともに、割り板の先端面によ
    る絞り込みによって型穴内に収まっている素材の端部側
    に連結部を形成し、さらに上記各分断片をそれぞれ鍛伸
    して二つのウェブを形成するとともに、前記型の開放面
    の高さ位置が、連結部絞り込み面の最高さ位置を基準に
    して、該位置における連結部の高さ方向の肉厚をtとし
    て、−0.6t〜0.6tの範囲内にあることを特徴と
    する二股形状鍛造品の製造方法。
    (57) [Claim 1] In a method for manufacturing a forked product comprising two opposed webs and a connecting portion formed between one end of both webs, the forged product is processed. that after only material end side of the connecting portion material is formed of massive installed on the type of shallow mold cavity shaped to fit within the mold cavity, forging upset
    And, subsequently, by press-fitting the split plate from the other end of the material the material while cutting the one side of the material, the connecting portion on the end side of the material is within a mold cavity by Filter by front end surface of the split plate And further forging each of the above-mentioned pieces to form two webs, and the open surface of the mold.
    Height position is based on the highest position of the joint narrowing surface
    Then, the thickness in the height direction of the connecting portion at the position is defined as t.
    A forked product having a forked shape, wherein the forged product is in the range of -0.6t to 0.6t .
JP9806997A 1997-03-31 1997-03-31 Manufacturing method of bifurcated forgings Expired - Fee Related JP3437404B2 (en)

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JP4482546B2 (en) * 2006-09-28 2010-06-16 株式会社神戸製鋼所 Cast steel throw for cast steel crankshaft and cast steel throw for cast steel crankshaft
CN100415408C (en) * 2006-11-01 2008-09-03 中国科学院金属研究所 Equipment for bend-forging crank axle toggle of large ship and method for forging the same
JP4482548B2 (en) * 2006-11-22 2010-06-16 株式会社神戸製鋼所 Casting method of cast steel throw for cast steel crankshaft
CN101823115B (en) * 2010-04-20 2012-06-27 华南理工大学 Method for eliminating method of inner cavity of shaft type heavy forged piece
CN101920304B (en) * 2010-06-30 2012-05-23 华南理工大学 Method for forging large steel shaft forging
CN107030452B (en) * 2017-05-09 2019-03-22 江苏创一精锻有限公司 A kind of automobile long handle sliding sleeve moulding process

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