JP2004114134A - Method for manufacturing forging having dissimilar inside diameter profile - Google Patents

Method for manufacturing forging having dissimilar inside diameter profile Download PDF

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Publication number
JP2004114134A
JP2004114134A JP2002284165A JP2002284165A JP2004114134A JP 2004114134 A JP2004114134 A JP 2004114134A JP 2002284165 A JP2002284165 A JP 2002284165A JP 2002284165 A JP2002284165 A JP 2002284165A JP 2004114134 A JP2004114134 A JP 2004114134A
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Japan
Prior art keywords
inner diameter
product
forging
molded product
diameter portion
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JP2002284165A
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Japanese (ja)
Inventor
Masahiro Sawai
沢井 政弘
Yoshikazu Kanazawa
金澤 嘉和
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.)
Tanaka Seimitsu Kogyo Co Ltd
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Tanaka Seimitsu Kogyo Co Ltd
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Application filed by Tanaka Seimitsu Kogyo Co Ltd filed Critical Tanaka Seimitsu Kogyo Co Ltd
Priority to JP2002284165A priority Critical patent/JP2004114134A/en
Publication of JP2004114134A publication Critical patent/JP2004114134A/en
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially favorable manufacturing method of a forging having an excellent inside diameter profile. <P>SOLUTION: A forging is manufactured by restricting both end faces and the outside diameter portion of a rough forging without restricting an extraction side peripheral edge portion on one end face of the rough forging on which the inside diameter profile punch of the rough forging with an inside diameter portion internally extracted is abutted, forging the inside diameter portion of the rough forging by the inside diameter profile punch, and forming pads on a non-restricted portion. <P>COPYRIGHT: (C)2004,JPO

Description

【0001】
【発明に属する技術分野】
本発明は、異形な内径プロファイルを有する鍛造品の製造方法に関するものである。
【0002】
【従来の技術】
従来、異形な内径プロファイルを有する鍛造品の製造方法としては、例えばオートバイ等に使用されるスターティングカムボディの鍛造方法が知られている。スターティングカムボディとは、通常内径部にローラ転動溝(カムプロファイル)と内周円とを結ぶ異形なプロファイル部を有する中空円板状部品である。この鍛造方法は、予め内径部を中抜きした粗成形品をダイ内のワークセット部に挿入し、この粗成形品の外径部を拘束しつつ、両端面を固定し、パンチを粗成形品の内径部に挿入し、余肉を打ち抜くという冷間鍛造方法である(特許文献1参照)。
【0003】
【特許文献1】
特開平11−333544号公報
【0004】
【発明が解決しようとする課題】
上記従来公知の鍛造方法では、粗成形品の外径部を拘束し、且つ両端面を固定しながら鍛造成形するため、鍛造時の肉の流れが少なく、このため、製品として機能する内径プロファイル部に打ち抜き加工時の欠陥(剥離、バリ等)が発生し、この欠陥が製品の内径プロファイル部に除去されきれずに残存し、不良品の原因となる問題がある。特に異形な内径プロファイル部を有する製品では、工業的生産上、この欠陥を除去する後加工が非常に困難であるため、この欠陥がしばしば工業的生産にとって大きな問題となる。
さらに、上記のように粗成形品をほぼ全域に渡って拘束すれば、肉の流れが少なくなるため、非常に大きな成形荷重が必要となり、よって、金型寿命が短命化し、生産効率が悪くなるという問題もある。
本発明はかかる事情に鑑みてなされたものであり、上記課題を解決して、工業的有利な良好な内径プロファイルを有する鍛造品の製造方法を提供することを目的とする。
【0005】
【課題を解決するための手段】
上記課題を解決するため、本発明者らは鋭意検討した結果、内径部を中抜きした粗成形品の(イ)内径プロファイルパンチが当接する当該粗成形品の一端面の抜け側周縁部と所望によりさらに(ロ)外径部の一部とを拘束せず、当該粗成形品のその他の両端面と外径部とを金型にて拘束した後、当該粗成形品の内径部を内径プロファイルパンチで鍛造成形し、非拘束部に余肉部を形成させることで、良好な内径プロファイル形状を有する鍛造品を容易に且つ工業的有利に製造できることを知見した。尚、前記余肉部とは、前記内径プロファイルパンチによる鍛造代を打ち抜くことによって、上記拘束されない前記内径プロファイルパンチが当接する前記粗成形品の一端面の抜け側周縁部と外径部の一部に形成される肉部分をいう。尚、ここでいう肉とは、鍛造品の素材、例えば鋼材をいう。
【0006】
また本発明者らは、前記内径プロファイルパンチが前記粗成形品の案内部を備えており、前記鍛造成形がしごき加工にて行われ、前記余肉部形成後に前記余肉部が例えば端面切削加工にて除去されることで、より好適に異形な内径プロファイル形状を有する鍛造品を製造できることも知見した。
さらに本発明者らは、前記外径部の拘束幅tが、前記外径部の全幅Tに対し、T×0.1≦t≦T×0.5とし、また、金型に拘束されている粗成形品への加圧を緩衝する背圧装置が設けられ、背圧力が加圧力に対し1〜3%となるように設定されていることで、成形荷重を軽減させ、それに伴い金型の長寿命化が図れるようになり、また、鍛造時の粗成形品の反りを抑制することもできるため、より有利に良質な製品が製造できることをも知見した。
本発明者らは、このような知見を得て、さらに種々検討を重ねて本発明を完成させるに至った。
【0007】
したがって本発明は、
(1) 内径部を中抜きした粗成形品の内径プロファイルパンチが当接する当該粗成形品の一端面の抜け側周縁部を拘束せず、当該粗成形品のその他の両端面と外径部とを金型にて拘束した後、当該粗成形品の内径部を内径プロファイルパンチで鍛造成形し、非拘束部に余肉部を形成させることを特徴とする異形な内径プロファイルを有する鍛造品の製造方法、
(2) さらに前記粗成形品の外径部の一部をも拘束せず、その他の外径部を金型にて拘束することを特徴とする(1)記載の異形な内径プロファイルを有する鍛造品の製造方法、
(3) 前記内径プロファイルパンチが前記粗成形品の案内部を備えており、前記鍛造成形がしごき加工にて行われ、前記余肉部形成後に前記余肉部が端面切削加工にて除去されることを特徴とする(1)または(2)記載の異形な内径プロファイルを有する鍛造品の製造方法、
(4) 前記外径部の拘束幅tが、前記外径部の全幅Tに対し、T×0.1≦t≦T×0.5であることを特徴とする(1)ないし(3)のいずれかに記載の異形な内径プロファイルを有する鍛造品の製造方法、
(5) 金型に拘束されている粗成形品への加圧を緩衝する背圧装置が設けられ、背圧力が加圧力に対し1〜3%となるように設定されていることを特徴とする(1)ないし(4)のいずれかに記載の異形な内径プロファイルを有する鍛造品の製造方法、
(6) (1)ないし(5)のいずれかに記載の製造方法にて成形された鍛造品、
に関する。
【0008】
【発明の実施の形態】
以下、本発明の好ましい実施の形態を添付図面に示した実施例に基づいて説明する。図1〜図9は本発明の実施例を示すものであり、図1は本発明の製造方法にて製造される鍛造品の成形前後の一例を示す平面図である。図2は本発明の製造方法のための鍛造設備の一例を示す概略構成図である。図3は図2の指定個所40の部分拡大図であり、内径部を中抜きした粗成形品を金型内にセットしたときの状態を示すものである。図4は図3に示す当該粗成形品のセット後に当該粗成形品をパンチとノックアウトで拘束したときの状態を示すものである。図5は図4の状態でパンチを降下させ、当該粗成形品の内径部を鍛造成形しているときの状態を示すものである。図6は図5の状態でしごき加工しているときの状態を示すものである。図7は鍛造成形直後の状態を示すものである。図8は当該粗成形品の外径部の拘束率[(拘束幅t/全幅T)×100]と当該粗成形品の内径部を鍛造成形する際の成形荷重との関係、および当該背圧装置の背圧力を成形荷重に対し1%または3%に設定した際の前記外形部の拘束率と当該鍛造品の反り量との関係を示すものである。図9は本発明方法と従来公知の製造方法にて鍛造成形されたそれぞれの鍛造品の内径プロファイル面を示す外観写真である。
【0009】
先ず図1を参照して、本発明を用いることで好適に鍛造成形できる製品としては、例えばオートバイ等に使用されるスターティングカムボディ等の内径部に異形なプロファイル形状を有する中空円板状部品20が挙げられる。この部品は内径部21にローラ転動溝22を3ヵ所有する製品であり、このローラ転動溝22が機能上重要な役割を果たすため、所望される形状は実際には工業生産上複雑であり、且つ高い寸法精度が要求される。よって、予め内径部を中抜きした粗成形品23の斜線部に示す個所を、欠陥(剥離、バリ等)無く、且つ寸法精度良く打ち抜かなければならない。また、図示はしないが、内径部にスプライン状の歯を有するような機能部品においても同様の精度が求められる。
【0010】
図2を併せて参照して、本発明の製造方法は例えば図2に示すような鍛造設備(金型)50で可能であり、この鍛造設備50は、好ましくは、(イ)内径部を中抜きした粗成形品30の上記した一部を拘束し、且つ所定の下死点Dの位置まで押圧するパンチ31と、(ロ)前記粗成形品30の上記した他部を拘束し、且つ鍛造成形後の鍛造品を金型外へ排出するノックアウト32と、(ハ)前記ノックアウト32を前記排出方向に押し出すノックアウトピン33と、(ニ)内径部を所望形状に鍛造成形する内径プロファイルパンチ34と、(ホ)前記ノックアウト32の下方で、前記パンチ31の押圧方向に対し受圧方向に前記粗成形品30を支持する背圧装置(ガスクッション)35と、(ヘ)前記パンチ31と前記ノックアウト32と前記内径プロファイルパンチ34とを画設するダイ36とから構成される。
【0011】
図3を併せて参照して、予め熱間鍛造等にて内径部を中抜きした鋼製の粗成形品30の内径部を、前記内径プロファイルパンチ34の先端部34aにて当設させつつ、前記粗成形品30の一端面とこの一端面に通じる外径部の一部とを前記ノックアウト32の上端面32a上に載置する。
【0012】
図4を併せて参照して、次に前記粗成形品30の他端面とこの他端面に通じる外径部の他部とを前記パンチ31の下端面31aにて一端定着させ、前記粗成形品30を拘束した状態で金型内にセットする。ここで、丸で囲んだ前記先端部34aが当接する前記粗成形品30の抜け側周縁部30aと、さらに所望により楕円で囲んだ前記粗成形品30の非拘束外径部30bとを、前記粗成形品30を金型内にセットする際と打ち抜き加工時に拘束しないことが本発明の特徴である。尚、内径側にある鍛造代30cは長方形で囲まれた箇所である。
【0013】
図5を併せて参照して、前記粗成形品30に一端定着させた前記パンチ31を再び稼動させ、前記粗成形品30の前記鍛造代30cを前記内径プロファイルパンチ34の円錐状の案内部34bにて当接させた状態で、前記パンチ31を前記ノックアウト32側に押圧し、前記鍛造代30cを前記抜け側周縁部30a側に排除しながら、丸で囲んだ余肉部30dを形成させつつ鍛造成形を行う。
【0014】
図6を併せて参照して、この際、前記案内部34bを前記鍛造代30cに対し、前記粗成形品30の中心軸のスラスト方向に間欠的に繰り返し押圧するしごき加工にて鍛造成形することで、より面性状に優れる内径プロファイル面を有する鍛造品を製造することが可能である。
【0015】
図7を併せて参照して、鍛造成形にて前記鍛造代30cが抜け側周縁部30a側にすべて排除され、前記余肉部30dを形成し、前記内径プロファイルパンチ34の外周部34cが鍛造品37の内径プロファイル部を貫通させる。その後、押圧していた前記パンチ31を押圧方向とは反対側の上死点Uの位置まで上昇させ、前記鍛造品37を拘束していた状態を解除し、さらに図2に示す前記ノックアウトピン33を前記ノックアウト32を介して前記鍛造品37側に押し出すように稼動させ、前記鍛造品37を前記内径プロファイルパンチ34から抜き取り、且つ前記鍛造設備50内から排出する。
尚、排出された前記鍛造品37には、前記余肉部30dが形成されているため、鍛造成形後に端面切削加工を行い、前記余肉部30dを除去することで、欠陥(剥離、バリ等)の無い良好な内径プロファイル部を有する製品を製造することができる。
本発明は、上記実施例に基づき鍛造することで製造できるが、本発明者らによる更なる鋭意検討の結果、以下に記す技術的事項を本製法に反映させることによって、より好ましい鍛造品が得られる。
【0016】
図8を併せて参照して、このグラフは、前記粗成形品30の外径部の拘束率[(拘束幅t/全幅T)×100]と前記粗成形品30の内径部を鍛造成形する際の成形荷重との関係、および前記背圧装置35の背圧力を成形荷重に対し1%または3%に設定した際の前記外形部の拘束率と前記鍛造品37の反り量との関係を示すものである。この結果、前記拘束幅tは前記外径部の全幅Tに対し、T×0.1≦t≦T×0.5に設定することが望ましいと分かり、本発明による鍛造時の成形荷重は、従来公知のおおよそ半分に設定することができるようになり、金型寿命の長寿命化を図ることができる。このようにして、背圧効果により前記粗成形品30の鍛造成形時の反りが抑えられるため、良好な内径プロファイル部を有する鍛造品の製造が可能となる。
【0017】
図9を併せて参照して、従来公知の鍛造方法では、例えば丸で囲んだような欠陥(剥離、バリ)が内径プロファイル面上にしばしば発生していた。本発明の製造方法を用いることによって、従来公知の鍛造方法でよく発生していた欠陥(剥離、バリ等)が無い、より良好な内径プロファイル面を成形することができる。また、製品の面性状においてもより優れていることが分かる。
【0018】
【発明の効果】
本発明の鍛造方法によって、良好な形状と面性状を併せもつ異形な内径プロファイルを有する鍛造品が工業的有利に製造できる。しかも、例えば端面切削等の簡単な後加工によって、容易に鍛造品に残存する余肉部を除去することができ、従来製造方法では除去が困難であった内径プロファイル上の欠陥(剥離、バリ等)は、本発明方法による製品には実質的に存在しない。したがって、本発明方法は工業的有利に異形な内径プロファイルを有する鍛造品を製造できる。
さらに、本発明方法は鍛造成形時の成形荷重に対して、外径部の拘束幅tを外径部の全幅Tに対し、T×0.1≦t≦T×0.5を満足するよう設定し、且つ鍛造設備内に背圧装置を設け、その背圧力を成形荷重に対し1〜3%となるように設定することで、鍛造品の反りを抑えつつ、しかも成形荷重を半減させることができるため、金型寿命の長寿命化を図ることもできる。
【図面の簡単な説明】
【図1】本発明の製造方法にて製造される鍛造品の成形前後の一例を示す平面図。
【図2】本発明の製造方法のための鍛造設備の一例を示す概略構成図。
【図3】図2の指定個所40の部分拡大図であり、内径部を中抜きした粗成形品を金型内にセットしたときの状態を示す。
【図4】図3に示す当該粗成形品のセット後に当該粗成形品をパンチとノックアウトで拘束したときの状態を示す。
【図5】図4の状態でパンチを降下させ、当該粗成形品の内径部を鍛造成形しているときの状態を示す。
【図6】図5の鍛造成形をしごき加工で行っているときの状態を示す。
【図7】鍛造成形直後の状態を示す。
【図8】当該粗成形品の外径部の拘束率[(拘束幅t/全幅T)×100]と当該粗成形品の内径部を鍛造成形する際の成形荷重との関係、および当該背圧装置の背圧力を成形荷重に対し1%または3%に設定した際の前記外形部の拘束率と当該鍛造品の反り量との関係を示す。
【図9】本発明方法と従来公知の製造方法にて鍛造成形されたそれぞれの鍛造品の内径プロファイル面を示す外観写真。
【符号の説明】
20・・・中空円板状部品
21・・・内径部
22・・・ローラ転動溝
23・・・粗成形品
30・・・粗成形品
30a・・・抜け側周縁部
30b・・・非拘束外径部
30c・・・鍛造代
30d・・・余肉部
31・・・パンチ
31a・・・下端面
32・・・ノックアウト
32a・・・上端面
33・・・ノックアウトピン
34・・・内径プロファイルパンチ
34a・・・先端部
34b・・・案内部
35・・・背圧装置(ガスクッション)
36・・・ダイ
37・・・鍛造品
50・・・鍛造設備(金型)
U・・・上死点
D・・・下死点
[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a forged product having an irregular inner diameter profile.
[0002]
[Prior art]
Conventionally, as a method of manufacturing a forged product having an irregular inner diameter profile, a forging method of a starting cam body used for a motorcycle or the like is known. The starting cam body is a hollow disk-shaped component having an irregularly shaped profile portion that connects a roller rolling groove (cam profile) and an inner circumferential circle in an inner diameter portion. In this forging method, a rough molded product whose inner diameter has been previously hollowed out is inserted into a work set part in a die, and both ends are fixed while restraining the outer diameter of the rough molded product. (See Patent Document 1).
[0003]
[Patent Document 1]
JP-A-11-333544
[Problems to be solved by the invention]
In the above-described conventionally known forging method, the outer diameter portion of the roughly formed product is restrained, and forging is performed while fixing both end faces, so that the flow of meat at the time of forging is small, and therefore, the inner diameter profile portion functioning as a product During the punching process, defects (peeling, burrs, etc.) occur at the time of punching, and the defects remain without being completely removed in the inner diameter profile portion of the product, causing a problem of defective products. In particular, in the case of a product having an irregular inner diameter profile portion, it is very difficult to remove the defect in industrial production, so that the defect is often a serious problem in industrial production.
Furthermore, if the roughly formed product is confined over almost the entire area as described above, the flow of meat is reduced, so a very large forming load is required, and therefore, the life of the mold is shortened and the production efficiency is deteriorated. There is also a problem.
The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above-mentioned problems and to provide a method for manufacturing a forged product having a favorable inner diameter profile which is industrially advantageous.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventors have made intensive studies and found that (a) a rough molded product having an inner diameter portion hollowed out and a desired peripheral edge portion of one end face of the rough molded product with which the inner diameter profile punch contacts. Then, (b) without restraining a part of the outer diameter portion, after constraining the other end surfaces and the outer diameter portion of the rough molded product by a mold, the inner diameter portion of the rough molded product is defined by an inner diameter profile. It has been found that a forged product having a good inner diameter profile shape can be easily and industrially advantageously produced by forging with a punch and forming a surplus portion in an unconstrained portion. In addition, by punching a forging allowance by the inner diameter profile punch, the extra thickness portion is a part of the outer peripheral portion and the outer peripheral portion on the one end surface of the rough molded product with which the unrestricted inner profile punch abuts. Means the meat part formed in Here, the meat refers to a material of a forged product, for example, a steel material.
[0006]
In addition, the present inventors provide that the inner diameter profile punch includes a guide portion of the rough molded product, the forging is performed by ironing, and the excess portion is formed by, for example, end face cutting after the excess portion is formed. It has also been found that by being removed in the above, a forged product having an irregular inner diameter profile shape can be produced more suitably.
Furthermore, the present inventors set the constraint width t of the outer diameter portion to be T × 0.1 ≦ t ≦ T × 0.5 with respect to the entire width T of the outer diameter portion, and A back pressure device is provided to buffer the pressure applied to the rough molded product, and the back pressure is set to be 1 to 3% of the pressing force, so that the molding load is reduced and the mold is accordingly It has also been found that a high-quality product can be produced more advantageously because it is possible to prolong the service life and to suppress the warpage of the roughly formed product during forging.
The present inventors have obtained such findings, and have conducted various studies to complete the present invention.
[0007]
Therefore, the present invention
(1) The outer peripheral portion of one end face of the rough molded product, which is contacted with the inner diameter profile punch of the rough molded product having an inner diameter portion hollowed out, is not restricted, and the other end surfaces and the outer diameter portion of the rough molded product are not restricted. Manufacturing the forged product having an irregular inner diameter profile, wherein the inner diameter portion of the roughly formed product is forged with an inner diameter profile punch to form a surplus portion in the non-constrained portion. Method,
(2) The forging having an irregular inner diameter profile according to (1), wherein a part of the outer diameter part of the rough molded product is not restricted, and the other outer diameter part is restricted by a mold. Product manufacturing method,
(3) The inner diameter profile punch is provided with a guide portion for the rough molded product, the forging is performed by ironing, and after forming the excess portion, the excess portion is removed by end face cutting. A method for producing a forged product having an irregular inner diameter profile according to (1) or (2),
(4) The constraint width t of the outer diameter portion is T × 0.1 ≦ t ≦ T × 0.5 with respect to the total width T of the outer diameter portion, (1) to (3). A method for producing a forged product having an irregular inner diameter profile according to any of the above,
(5) A back pressure device is provided for buffering the pressurization of the roughly formed product constrained by the mold, and the back pressure is set so as to be 1 to 3% with respect to the pressing force. (1) A method for producing a forged product having an irregular inner diameter profile according to any one of (1) to (4),
(6) A forged product formed by the method according to any one of (1) to (5),
About.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described based on examples shown in the accompanying drawings. 1 to 9 show an embodiment of the present invention, and FIG. 1 is a plan view showing an example before and after forming of a forged product manufactured by the manufacturing method of the present invention. FIG. 2 is a schematic configuration diagram showing an example of a forging facility for the production method of the present invention. FIG. 3 is a partially enlarged view of the designated portion 40 in FIG. 2, and shows a state in which a roughly formed product having an inner diameter portion hollowed out is set in a mold. FIG. 4 shows a state in which the rough molded product is restrained by punching and knocking out after setting the coarse molded product shown in FIG. FIG. 5 shows a state in which the punch is lowered in the state of FIG. 4 and the inner diameter portion of the roughly formed product is forged. FIG. 6 shows a state when ironing is performed in the state of FIG. FIG. 7 shows a state immediately after forging. FIG. 8 shows the relationship between the constraint rate of the outer diameter portion of the rough molded product [(constraint width t / total width T) × 100] and the forming load when forging the inner diameter portion of the rough molded product, and the back pressure. It shows the relationship between the restraint rate of the outer portion and the amount of warpage of the forged product when the back pressure of the device is set to 1% or 3% with respect to the forming load. FIG. 9 is an external appearance photograph showing an inner diameter profile surface of each forged product forged by the method of the present invention and a conventionally known manufacturing method.
[0009]
First, referring to FIG. 1, a product that can be suitably forged by using the present invention is, for example, a hollow disc-shaped component having an irregular profile shape on an inner diameter portion of a starting cam body or the like used for a motorcycle or the like. 20. This part is a product having three roller rolling grooves 22 in the inner diameter portion 21. Since the roller rolling grooves 22 play an important role in function, the desired shape is actually complicated in industrial production. And high dimensional accuracy is required. Therefore, it is necessary to punch out a portion indicated by a hatched portion of the rough molded product 23 in which the inner diameter portion has been previously hollowed without defects (peeling, burrs, etc.) and with high dimensional accuracy. Although not shown, similar accuracy is required for functional components having spline-shaped teeth at the inner diameter.
[0010]
Referring also to FIG. 2, the manufacturing method of the present invention can be performed by, for example, a forging facility (die) 50 as shown in FIG. 2. A punch 31 for restraining the above-mentioned part of the rough molded product 30 and pressing it to the position of the predetermined bottom dead center D; (b) for restraining the other part of the rough molded product 30 and forging A knockout 32 for discharging the formed forged product out of the mold, (c) a knockout pin 33 for pushing the knockout 32 in the discharge direction, and (d) an inner diameter profile punch 34 for forging the inner diameter into a desired shape. (E) a back pressure device (gas cushion) 35 for supporting the roughly formed product 30 in a pressure receiving direction with respect to a pressing direction of the punch 31 below the knockout 32, and (f) the punch 31 and the knockout 32. And before Constructed and inner diameter profile punch 34 from the die 36 for E設.
[0011]
Referring also to FIG. 3, while the inner diameter portion of the steel rough formed product 30 whose inner diameter portion has been previously hollowed out by hot forging or the like is abutted at the distal end portion 34 a of the inner diameter profile punch 34, One end surface of the roughly formed product 30 and a part of the outer diameter portion communicating with the one end surface are placed on the upper end surface 32 a of the knockout 32.
[0012]
Referring also to FIG. 4, the other end surface of the roughly formed product 30 and the other portion of the outer diameter portion communicating with the other end surface are once fixed at the lower end surface 31 a of the punch 31, 30 is set in a mold while being restrained. Here, the marginal side peripheral portion 30a of the rough molded product 30 that the tip portion 34a surrounded by a circle abuts, and the unconstrained outer diameter portion 30b of the coarse molded product 30 further surrounded by an ellipse, if desired, It is a feature of the present invention that the rough molded product 30 is not constrained when it is set in a mold and when it is punched. The forging allowance 30c on the inner diameter side is a portion surrounded by a rectangle.
[0013]
Referring also to FIG. 5, the punch 31 once fixed to the rough molded product 30 is operated again, and the forging allowance 30 c of the rough molded product 30 is conveyed to the conical guide portion 34 b of the inner diameter profile punch 34. The punch 31 is pressed against the knockout 32 in a state where the forging allowance 30c is removed toward the pull-out side peripheral portion 30a while forming a surplus portion 30d surrounded by a circle. Perform forging.
[0014]
At this time, with reference to FIG. 6, at this time, forging is performed by ironing in which the guide portion 34 b is repeatedly and intermittently pressed against the forging allowance 30 c in the thrust direction of the center axis of the rough molded product 30. Thus, it is possible to produce a forged product having an inner diameter profile surface having more excellent surface properties.
[0015]
Referring also to FIG. 7, the forging allowance 30 c is entirely removed on the side of the peripheral side edge 30 a by forging, forming the excess portion 30 d, and the outer peripheral portion 34 c of the inner diameter profile punch 34 is a forged product. 37 through the inner diameter profile. Thereafter, the pressed punch 31 is raised to the position of the top dead center U on the side opposite to the pressing direction to release the state in which the forged product 37 is restrained, and the knockout pin 33 shown in FIG. Is operated so as to be pushed toward the forged product 37 through the knockout 32, and the forged product 37 is extracted from the inner diameter profile punch 34 and discharged from the forging equipment 50.
In addition, since the surplus portion 30d is formed on the discharged forged product 37, an end face cutting process is performed after forging, and the surplus portion 30d is removed, so that a defect (peeling, burr, etc.) is generated. ), A product having a good inner diameter profile portion without) can be manufactured.
Although the present invention can be manufactured by forging based on the above-described embodiment, as a result of further intensive studies by the present inventors, a more preferable forged product is obtained by reflecting the technical matters described below in the present manufacturing method. Can be
[0016]
Referring to FIG. 8 together, this graph shows that the constraining rate of the outer diameter portion of the rough molded product 30 [(constraint width t / total width T) × 100] and the inner diameter portion of the rough molded product 30 are forged. And the relationship between the restraint rate of the outer portion and the amount of warpage of the forged product 37 when the back pressure of the back pressure device 35 is set to 1% or 3% of the forming load. It is shown. As a result, it was found that the constraint width t was desirably set to T × 0.1 ≦ t ≦ T × 0.5 with respect to the entire width T of the outer diameter portion, and the forming load during forging according to the present invention was: This can be set to about half the conventionally known value, and the life of the mold can be extended. In this way, the warpage during the forging of the roughly formed product 30 is suppressed by the back pressure effect, so that a forged product having a good inner diameter profile can be manufactured.
[0017]
Referring to FIG. 9 together, in the conventionally known forging method, for example, defects (peeling, burrs) surrounded by a circle often occurred on the inner diameter profile surface. By using the manufacturing method of the present invention, it is possible to form a better inner diameter profile surface free from defects (peeling, burrs, etc.) that often occur by a conventionally known forging method. Further, it can be seen that the surface properties of the product are more excellent.
[0018]
【The invention's effect】
According to the forging method of the present invention, a forged product having an irregular inner diameter profile having both good shape and good surface properties can be industrially advantageously produced. In addition, a surplus portion remaining in the forged product can be easily removed by simple post-processing such as end face cutting, and defects (exfoliation, burrs, etc.) on the inner diameter profile which have been difficult to remove by the conventional manufacturing method. ) Is substantially absent in products according to the method of the invention. Therefore, the method of the present invention can produce forgings having an irregular inner diameter profile in an industrially advantageous manner.
Furthermore, the method of the present invention is such that, with respect to the forming load during forging, the constraint width t of the outer diameter portion satisfies T × 0.1 ≦ t ≦ T × 0.5 with respect to the entire width T of the outer diameter portion. By setting the back pressure device in the forging equipment and setting the back pressure to be 1 to 3% of the forming load, the warpage of the forged product can be suppressed and the forming load can be reduced by half. Therefore, the life of the mold can be extended.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example before and after forming of a forged product manufactured by a manufacturing method of the present invention.
FIG. 2 is a schematic configuration diagram showing an example of a forging facility for the production method of the present invention.
FIG. 3 is a partially enlarged view of a designated portion 40 of FIG. 2 and shows a state in which a roughly molded product with an inner diameter portion hollowed out is set in a mold.
FIG. 4 shows a state in which the roughly formed product is restrained by a punch and a knockout after setting the roughly formed product shown in FIG. 3;
5 shows a state in which the punch is lowered in the state of FIG. 4 and the inner diameter portion of the roughly formed product is forged.
6 shows a state when the forging of FIG. 5 is performed by ironing.
FIG. 7 shows a state immediately after forging.
FIG. 8 shows the relationship between the constraint rate of the outer diameter portion of the rough molded product [(constraint width t / total width T) × 100] and the forming load when forging the inner diameter portion of the rough molded product, and the spine. 4 shows the relationship between the restraint rate of the outer portion and the amount of warpage of the forged product when the back pressure of the pressure device is set to 1% or 3% of the forming load.
FIG. 9 is an external view photograph showing the inner diameter profile surface of each forged product forged by the method of the present invention and a conventionally known manufacturing method.
[Explanation of symbols]
Reference numeral 20: hollow disk-shaped part 21: inner diameter portion 22: roller rolling groove 23: rough molded product 30: coarse molded product 30a: peripheral edge portion 30b: non-formed Restricted outer diameter portion 30c Forging allowance 30d Surplus portion 31 Punch 31a Lower end surface 32 Knockout 32a Upper end surface 33 Knockout pin 34 Inner diameter Profile punch 34a ··· Tip 34b ··· Guide 35 · Back pressure device (gas cushion)
36 ... Die 37 ... Forged product 50 ... Forging equipment (die)
U: Top dead center D: Bottom dead center

Claims (6)

内径部を中抜きした粗成形品の内径プロファイルパンチが当接する当該粗成形品の一端面の抜け側周縁部を拘束せず、当該粗成形品のその他の両端面と外径部とを金型にて拘束した後、当該粗成形品の内径部を内径プロファイルパンチで鍛造成形し、非拘束部に余肉部を形成させることを特徴とする異形な内径プロファイルを有する鍛造品の製造方法。Without restricting the outer peripheral edge of the rough molded product on one end face against which the inner diameter profile punch of the roughly molded product having the inner diameter portion hollowed out, the other end surfaces and the outer diameter portion of the rough molded product are molded. Characterized in that, after constrained by the above method, the inner diameter portion of the roughly formed product is forged with an inner diameter profile punch to form a surplus portion in the non-constrained portion. さらに前記粗成形品の外径部の一部をも拘束せず、その他の外径部を金型にて拘束することを特徴とする請求項1記載の異形な内径プロファイルを有する鍛造品の製造方法。2. The forged product having an irregular inner diameter profile according to claim 1, wherein a part of the outer diameter portion of the rough molded product is not restrained, and the other outer diameter portion is restrained by a mold. Method. 前記内径プロファイルパンチが前記粗成形品の案内部を備えており、前記鍛造成形がしごき加工にて行われ、前記余肉部形成後に前記余肉部が端面切削加工にて除去されることを特徴とする請求項1または2記載の異形な内径プロファイルを有する鍛造品の製造方法。The inner diameter profile punch includes a guide portion for the rough molded product, the forging is performed by ironing, and the excess portion is removed by end face cutting after the excess portion is formed. The method for producing a forged product having an irregular inner diameter profile according to claim 1 or 2. 前記外径部の拘束幅tが、前記外径部の全幅Tに対し、
T×0.1≦t≦T×0.5
であることを特徴とする請求項1ないし3のいずれかに記載の異形な内径プロファイルを有する鍛造品の製造方法。
The constraint width t of the outer diameter portion is, with respect to the total width T of the outer diameter portion,
T × 0.1 ≦ t ≦ T × 0.5
The method for producing a forged product having an irregular inner diameter profile according to any one of claims 1 to 3, characterized in that:
金型に拘束されている粗成形品への加圧を緩衝する背圧装置が設けられ、背圧力が加圧力に対し1〜3%となるように設定されていることを特徴とする請求項1ないし4のいずれかに記載の異形な内径プロファイルを有する鍛造品の製造方法。A back pressure device for buffering the pressurization of the rough molded product restrained by the mold is provided, and the back pressure is set to be 1 to 3% with respect to the pressing force. 5. A method for producing a forged product having an irregular inner diameter profile according to any one of 1 to 4. 請求項1ないし5のいずれかに記載の製造方法にて成形された鍛造品。A forged product formed by the manufacturing method according to claim 1.
JP2002284165A 2002-09-27 2002-09-27 Method for manufacturing forging having dissimilar inside diameter profile Pending JP2004114134A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8037731B2 (en) 2006-10-04 2011-10-18 Denso Corporation Forging method and forging apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8037731B2 (en) 2006-10-04 2011-10-18 Denso Corporation Forging method and forging apparatus

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