JPH1029033A - Rough-forging shape of crank shaft - Google Patents
Rough-forging shape of crank shaftInfo
- Publication number
- JPH1029033A JPH1029033A JP20664796A JP20664796A JPH1029033A JP H1029033 A JPH1029033 A JP H1029033A JP 20664796 A JP20664796 A JP 20664796A JP 20664796 A JP20664796 A JP 20664796A JP H1029033 A JPH1029033 A JP H1029033A
- Authority
- JP
- Japan
- Prior art keywords
- pin
- segregation
- crankshaft
- rough
- forging
- 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.)
- Pending
Links
Landscapes
- Forging (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、自動車エンジン
等の内燃機関に用いるクランク軸を鍛造法で製造する場
合の鍛造荒地形状に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape of a forged rough land when a crankshaft used for an internal combustion engine such as an automobile engine is manufactured by a forging method.
【０００２】[0002]
【従来の技術】自動車エンジン等に用いられるクランク
軸は、鍛造プレス等により製造され、回転基準位置から
所定角度位置となるように回転中心軸に沿って設けられ
たコネクティングロッドを取付けるための複数のピンお
よび回転バランスを取るためのカウンタウエイトと、両
端に設けられたジャーナルとから構成されている。ジャ
ーナルの断面形状は、クランク軸の中心線を中心とする
同心円であり、ピンの断面形状は、クランク軸の中心線
から離間した中心位置を有する円であり、カウンタウエ
イトの断面形状は、クランク軸の中心線から離間した中
心位置を有するほぼ扇形である。2. Description of the Related Art A crankshaft used for an automobile engine or the like is manufactured by a forging press or the like, and is provided with a plurality of connecting rods provided along a rotation center axis so as to be at a predetermined angle from a rotation reference position. It comprises a pin and a counterweight for balancing the rotation, and journals provided at both ends. The cross-sectional shape of the journal is a concentric circle centered on the centerline of the crankshaft, the cross-sectional shape of the pin is a circle having a center position separated from the centerline of the crankshaft, and the cross-sectional shape of the counterweight is Is substantially fan-shaped with a center position separated from the center line of the circle.
【０００３】上記クランク軸の製造工程は、図５に示す
とおり、断面が丸形あるいは四角形の鋼片５１を素材と
して用い、製品形状に応じた長手方向の体積配分と断面
形状を整え段付き軸５２に成形するためのロール加工、
歩留り向上のためにピンと反対側のカウンタウェイト側
に材料を移動偏心させることにより幅方向への体積配分
を行い曲げ軸５３とするための曲げ加工、製品形状に近
い形状にまで成形する荒打工程、製品形状のクランク軸
５４に仕上げる仕上打加工などからなる。As shown in FIG. 5, the crankshaft manufacturing process uses a round or square steel slab 51 as a raw material, adjusts the longitudinal volume distribution and cross-sectional shape according to the product shape, and adjusts the stepped shaft. Roll processing for forming into 52,
In order to improve the yield, the material is eccentrically moved to the counter weight side opposite to the pin to distribute the volume in the width direction and bend to form the bending shaft 53, and to form a shape close to the product shape. And finish punching to finish the crankshaft 54 in a product shape.
【０００４】上記クランク軸の製造における曲げ加工さ
れた素材は、荒打工程においてピン形成用凹部およびバ
ランスウエイト形成用凹部への素材の位置決めならびに
ジャーナル形成用凹部への素材の位置決めが不確実であ
るという問題点を有していた。[0004] In the raw material that has been bent in the manufacture of the crankshaft, the positioning of the raw material in the concave portion for forming the pin and the concave portion for forming the balance weight and the positioning of the raw material in the concave portion for forming the journal in the roughing process are uncertain. There was a problem that.
【０００５】上記問題点を解消する方法としては、ピン
およびその両側のバランスウエイト部に対応するクラン
クスロー部外周の軸線方向中央に前記軸線および一直径
線と直交する方向に延びる一対の嵌合溝を形成し、前記
クランクスロー部の嵌合溝およびジャーナル部で前記素
材を位置決めし得る凹所をそれぞれ有する上下の型から
なる荒鍛造用金型で、前記クランクスロー部をピン側に
肉寄せしながら、ばりの流出をその流出方向に対する傾
斜段差面で規制して荒鍛造を行い、仕上鍛造用金型で、
ばりの流出をその流出方向に対する傾斜段差面で規制し
ながら仕上鍛造する方法（特開昭６０−２７４４０号公
報）が提案されている。As a method of solving the above problem, a pair of fitting grooves extending in a direction perpendicular to the axis and the one-diameter line are provided at the axial center of the outer periphery of the crank throw portion corresponding to the pin and the balance weights on both sides thereof. Forming a rough forging die comprising upper and lower dies each having a recess capable of positioning the material in the fitting groove and the journal portion of the crank throw portion, and moving the crank throw portion to the pin side. While, the outflow of the burrs is regulated by the inclined step surface to the outflow direction, and rough forging is performed.
A method has been proposed in which finish forging is performed while regulating the outflow of burrs on an inclined step surface with respect to the outflow direction (Japanese Patent Laid-Open No. 60-27440).
【０００６】[0006]
【発明が解決しようとする課題】上記クランク軸の製造
における荒地形状は、製品形状に応じた体積配分を効率
良く成形し、歩留り向上、鍛造圧の低減等を目的に成形
されている。しかしながら、例えば前記図５（ｃ）に示
す荒地形状の場合は、素材中心部の不純物が曲げ軸５３
の中心に偏析部５５として残留しているため、型打ち実
施後、内部のメタルフローを詳細に調査した結果、クラ
ンク軸ピン部５６表面に素材の偏析部５５が露出してい
ることがある。このような現象は、最も負荷（応力）の
かかるピン部５６付根に対する疲労強度ならびに品質の
低下につながる。また、他の荒地形状の場合にもいえる
（鋳片、ロール荒地を直接型打ちする場合等）。The rough land shape in the manufacture of the crankshaft is formed for the purpose of efficiently forming a volume distribution according to the product shape, improving the yield, and reducing the forging pressure. However, for example, in the case of the rough land shape shown in FIG.
The segregation portion 55 remains in the center of the material, and after performing the stamping, as a result of investigating the internal metal flow in detail, the segregation portion 55 of the material may be exposed on the surface of the crankshaft pin portion 56 in some cases. Such a phenomenon leads to a decrease in fatigue strength and quality for the root of the pin portion 56 to which the most load (stress) is applied. In addition, it can be applied to other rough land shapes (such as a case where a slab or a rolled rough land is directly stamped).
【０００７】この発明の目的は、上記従来技術の欠点を
解消し、材料の歩留りをダウンさせずにクランク軸ピン
部への中心偏析の露出を防止して品質の向上を図ること
ができるクランク軸鍛造荒地形状を提供することにあ
る。An object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to improve the quality of the crankshaft by preventing the center segregation from being exposed to the crankshaft pin portion without lowering the yield of the material. It is to provide a forged wasteland shape.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、上記目的
を達成すべく予備検討としてクランク軸の部分モデル、
すなわち２枚のカウンタウェイトとその間のピン部位を
対象にプラスチシンを用いて基礎実験を行った。素材と
しては、単純な角柱を用意した。この発明の荒地形状
は、素材のカウンタウェイト間、すなわちピンを形成す
る部位に、板状の突起を打ち込む等の方法で鋳造により
形成されるカウンタウェイトからピン側に向かう局所的
に凹みを与えることによって、素材中心部の偏析部をピ
ン方向に移動させたのち、荒型、仕上型で型打ちテスト
を行った。Means for Solving the Problems The inventors of the present invention carried out preliminary studies on a partial model of a crankshaft,
That is, a basic experiment was performed using plastin for two counterweights and a pin portion therebetween. As a material, a simple prism was prepared. The rough land shape of the present invention is to provide a local recess toward the pin from the counterweight formed by casting by a method such as driving a plate-like projection between the counterweights of the raw material, that is, the portion forming the pin. After the segregated portion at the center of the material was moved in the pin direction, a stamping test was performed with a rough die and a finish die.
【０００９】得られた２枚のカウンタウェイトとその間
のピン部位は、内部のメタルフローを詳細に観察調査し
た結果、従来法の荒地形状のモデル実験では、ピンの表
面近くに素材中心部の偏析部が露出する偏析表出が現れ
たが、素材高さの１／３程度まで局所的に突起を打込ん
で局所的凹みを与えた荒地形状の場合には、素材中心部
の偏析部は完全に製品内、すなわちピン内に押し込まれ
ることを究明し、この発明に到達した。As a result of detailed observation of the internal metal flow, the segregation of the central part of the material near the surface of the pin was found in the conventional model experiment of the rough land with respect to the two counterweights and the pin portion therebetween. Although segregation appeared to expose the part, in the case of a rough terrain where local protrusions were given by locally projecting protrusions to about 1/3 of the material height, the segregation part at the center of the material was completely The inventors of the present invention have found that they are pushed into a product, that is, a pin, and have reached the present invention.
【００１０】すなわち、この発明の鍛造荒地は、カウン
タウェイト間のピンを形成する部位に、鋳造により形成
されるカウンタウェイトからピン側に向かう局所的凹み
を有する。このように、カウンタウェイト間のピンを形
成する部位に、鋳造により形成されるカウンタウェイト
からピン側に向かう局所的凹みを与えることによって、
素材中心部の偏析部位がピンを形成する部位方向に移動
し、仕上加工において素材中心部の偏析がピン内に封入
され、クランク軸ピン部への中心偏析の露出を防止する
ことができ、ピン部疲労強度の低下防止ならびに品質の
向上を図ることができる。[0010] That is, the forged wasteland of the present invention has a local dent toward the pin side from the counterweight formed by casting at a portion where the pin between the counterweights is formed. In this way, by giving a local recess toward the pin side from the counterweight formed by casting, at the portion forming the pin between the counterweights,
The segregation site at the center of the material moves in the direction of forming the pin, and the segregation at the center of the material is enclosed in the pin during finishing, preventing the center segregation from being exposed to the crankshaft pin. It is possible to prevent a decrease in the fatigue strength of the part and improve the quality.
【００１１】また、この発明の鍛造荒地は、カウンタウ
ェイト間のピンを形成する部位に、鋳造により形成され
るカウンタウェイトからピン側に向かう下記（１）〜
（２）式により求めた凹み高さ率（ｈ）が０．２〜０．
５、凹み幅率（ｔ）が０．５〜１．３の局所的凹みを有
する。 凹み高さ率（ｈ）＝（ＨＳ−ＨＥ）／ＨＳ……（１）式 凹み幅率（ｔ）＝ＭＷ／ＣＷ……（２）式 ただし、ＨＳ： 従来荒地高さ、ＨＥ： 本発明荒地高
さ、ＭＷ： 凹み幅、ＣＷ：カウンタウェイト間隔であ
る。In the forged wasteland of the present invention, the following (1) to (1) to the pin side from the counter weight formed by casting are formed at the portions where the pins between the counter weights are formed.
The dent height ratio (h) obtained by the equation (2) is 0.2 to 0.2.
5. It has a local dent having a dent width ratio (t) of 0.5 to 1.3. Depression height ratio (h) = (HS−HE) / HS Expression (1) Expression Width ratio (t) = MW / CW Expression (2) where HS: Conventional wasteland height, HE: The present invention Wasteland height, MW: recess width, CW: counter weight interval.
【００１２】このように、カウンタウェイト間のピンを
形成する部位に、鋳造により形成されるカウンタウェイ
トからピン側に向かう凹み高さ率（ｈ）が０．２〜０．
５、凹み幅率（ｔ）が０．５〜１．３の局所的凹みを与
えることによって、素材中心部の偏析部位がピンを形成
する部位方向に移動し、仕上加工において素材中心部の
偏析がピン内に封入され、クランク軸ピン部への中心偏
析の露出による表出を防止することができ、ピン部疲労
強度の低下防止ならびに品質の向上を図ることができ
る。As described above, in the portion where the pin is formed between the counterweights, the dent height ratio (h) from the counterweight formed by casting toward the pins is 0.2 to 0.1.
5. By providing a local dent having a dent width ratio (t) of 0.5 to 1.3, the segregation site at the center of the material moves in the direction of the pin forming portion, and segregation at the center of the material in the finishing process Can be prevented from being exposed due to the exposure of the center segregation to the crankshaft pin portion, and the deterioration of the pin portion fatigue strength can be prevented and the quality can be improved.
【００１３】[0013]
【発明の実施の形態】この発明の鍛造荒地は、クランク
軸ピン部への素材中心部の不純物偏析部の露出を防止す
るため、従来の鍛造荒地ではピン部表面に偏析部が露出
するので、クランク軸のピン部を形成する部位に、板状
の突起を打ち込む等の方法で鋳造により形成されるカウ
ンタウェイトからピン側に向かう局所的凹みを与えるの
である。本発明の鍛造荒地の局所的凹みは、図１に示す
とおり、従来の荒地高さをＨＳ、本発明の荒地高さをＨ
Ｅとした場合、前記（１）式によって求めた凹み高さ率
（ｈ）を０．２〜０．５の範囲とする。また、図１に示
すとおり、本発明荒地の凹み幅をＭＷ、クランク軸のカ
ウンタウェイト間隔をＣＷとした場合、前記（２）式に
よって求めた凹み幅率（ｔ）を０．５〜１．３の範囲と
する。BEST MODE FOR CARRYING OUT THE INVENTION In the forged wasteland of the present invention, in order to prevent the impurity segregation part in the center of the material from being exposed to the crankshaft pin part, the segregation part is exposed on the surface of the pin part in the conventional forged wasteland. A local recess toward the pin from the counterweight formed by casting is applied to a portion of the crankshaft where the pin portion is to be formed by, for example, driving a plate-like projection. As shown in FIG. 1, the local depression of the forged wasteland according to the present invention is such that the conventional wasteland height is HS and the wasteland height of the present invention is H.
In the case of E, the dent height ratio (h) obtained by the above equation (1) is in the range of 0.2 to 0.5. Also, as shown in FIG. 1, when the dent width of the wasteland of the present invention is MW and the interval between the counterweights of the crankshaft is CW, the dent width ratio (t) obtained by the above equation (2) is 0.5 to 1. 3 range.
【００１４】また、荒地に凹みを与える方法としては、
凸型の板状の突起を有した曲型を用いたり、他の荒地成
形段階の工程における金型を利用しても良い。例えば、
曲型に板状の突起を設けて曲げ加工と同時に局所的に凹
みを与えたりすることが考えられる。Further, as a method of giving a depression to a wasteland,
A curved mold having a convex plate-shaped projection may be used, or a mold in another rough land forming step may be used. For example,
It is conceivable to provide a plate-shaped projection on a curved shape to provide a local depression simultaneously with the bending process.
【００１５】この発明において前記（１）式によって求
めた凹み高さ率（ｈ）を０．２〜０．５としたのは、
０．２未満では疵や欠肉等の発生は見られないが、素材
中心部の偏析部がピン部表面に露出する偏析表出が発生
し、０．５を超えると素材中心部の偏析部がピン部表面
に露出する偏析表出は見られないが、疵やカウンタウェ
イト部への欠肉等が発生するからである。In the present invention, the dent height ratio (h) obtained by the above equation (1) is set to 0.2 to 0.5 because:
When less than 0.2, no flaws or underfilling are observed, but segregation at the center of the material is exposed on the pin surface. When it exceeds 0.5, the segregation at the center of the material is generated. This is because no segregation expression exposed on the surface of the pin portion is observed, but flaws and underfilling of the counterweight portion are generated.
【００１６】この発明において前記（２）式によって求
めた凹み幅率（ｔ）を０．５〜１．３としたのは、０．
５未満では疵や欠肉等の発生は見られないが、素材中心
部の偏析部がピン部表面に露出する偏析表出が発生し、
１．３を超えると素材中心部の偏析部がピン部表面に露
出する偏析表出は見られないが、疵やカウンタウェイト
部への欠肉等が発生するからである。In the present invention, the reason why the dent width ratio (t) obtained by the above equation (2) is 0.5 to 1.3 is that the dent width ratio is 0.5 to 1.3.
When it is less than 5, no flaw or underfilling is observed, but segregation at the center of the material is exposed on the pin surface,
If the ratio exceeds 1.3, no segregation expression in which the segregated portion at the center of the material is exposed on the surface of the pin portion is observed, but flaws and underfilling of the counterweight portion occur.
【００１７】[0017]
実施例１ 以下にこの発明の詳細を実施の一例を示す図１に基づい
て説明する。図１は４気筒８枚カウンタウェイトのクラ
ンク軸鍛造荒地形状の説明図で、（ａ）図はこの発明の
荒地形状の側面図、（ｂ）図は（ａ）図の鍛造荒地を荒
型、仕上型で型打ちして得た４気筒８枚カウンタウェイ
トのクランク軸、（ｃ）図は従来の荒地形状の側面図で
ある。図１（ｂ）において、クランク軸１は、気筒数に
応じた４つのピン２ａ〜２ｄがあり、各々のピン２ａ〜
２ｄを挟む２枚１組のカウンタウェイトを有するアーム
３ａ〜３ｄが計８枚存在する。この場合、クランク軸１
の長手方向外側に位置する２つのピン２ａ、２ｄを挟む
４枚のアーム３ａ、３ａ、３ｄ、３ｄと、内側に位置す
る２つのピン２ｂ、２ｃを挟む４枚のアーム３ｂ、３
ｂ、３ｃ、３ｃは、カウンタウェイトの位置する側がク
ランク軸１中心軸に対して互いに逆になる。Embodiment 1 Hereinafter, details of the present invention will be described with reference to FIG. 1 showing an embodiment. FIG. 1 is an explanatory view of a crankshaft forged wasteland shape of an eight-cylinder counterweight of four cylinders. FIG. 1 (a) is a side view of the wasteland shape of the present invention, FIG. 1 (b) is a roughened forged wasteland of FIG. Crankshaft of 8-cylinder, 8-cylinder counterweight obtained by stamping with a finishing die. FIG. 3 (c) is a side view of a conventional rough land shape. In FIG. 1B, the crankshaft 1 has four pins 2a to 2d corresponding to the number of cylinders.
There are a total of eight arms 3a to 3d having a pair of counterweights sandwiching 2d. In this case, the crankshaft 1
, Four arms 3a, 3a, 3d, 3d sandwiching two pins 2a, 2d located outside in the longitudinal direction, and four arms 3b, 3 sandwiching two pins 2b, 2c located inside.
As for b, 3c and 3c, the side where the counter weight is located is opposite to the center axis of the crankshaft 1.
【００１８】１２００℃に加熱された１１０ｍｍ角、長
さ４２０ｍｍのビレットを素材として用い、ロール加工
により軸方向に体積配分を持つ段付き軸に成形する。ロ
ール加工された段付き軸は、直ちに幅方向に体積配分を
行うための曲型で型打ちして曲げ加工した。曲型による
型打ちによる曲げ加工では、図１（ｃ）に示すとおり、
カウンタウェイトを充満させるために与える体積偏心
は、長手方向両端のピン２ａ、２ｄ相当部と内側のピン
２ｂ、２ｃ相当部で逆方向となる。この図１（ｃ）に示
すものが従来の鍛造荒地１１である。A billet of 110 mm square and 420 mm length heated to 1200 ° C. is used as a material and formed into a stepped shaft having a volume distribution in the axial direction by roll processing. The rolled stepped shaft was bent and stamped with a curved shape for immediate volume distribution in the width direction. In the bending process by stamping with a curved mold, as shown in FIG.
The volume eccentricity imparted to fill the counter weight is opposite in the direction corresponding to the pins 2a and 2d at both ends in the longitudinal direction and the parts corresponding to the inner pins 2b and 2c. FIG. 1C shows a conventional forged wasteland 11.
【００１９】次にこの偏心に対向する向きに曲型に板状
の突起を設けて曲げ加工と同時に、図１（ａ）に示すと
おり、局所的に凹み幅率（ｔ）：０〜１．３、凹み高さ
率（ｈ）：０〜０．６の凹み４ａ〜４ｄを与えた鍛造荒
地５とし、荒型、仕上型で型打ちしてクランク軸１とな
し、得られた各クランク軸のメタルフローを調査して凹
み幅率（ｔ）および凹み高さ率（ｈ）と型打後の偏析位
置を調査した。その結果を図３、図４に示す。Next, a plate-shaped projection is provided in a curved shape in a direction opposite to the eccentricity, and at the same time as the bending process, as shown in FIG. 3. Depth height ratio (h): Forged wasteland 5 provided with depressions 4a to 4d of 0 to 0.6, stamped with a rough die and a finish die to form a crankshaft 1, and each obtained crankshaft And the dent width ratio (t) and dent height ratio (h) and the segregation position after stamping were examined. The results are shown in FIGS.
【００２０】図３に示すとおり、凹み幅率（ｔ）が零の
従来荒地形状および凹み幅率（ｔ）が０．４２の荒地形
状では、素材中心部の偏析がピン部表面に露出する偏析
表出が見られ、凹み幅率ｔが１．３の荒地形状では、ピ
ン部表面への偏析表出が見られなかったが、製品形状に
疵が残り、カウンタウェイト部に欠肉が発生した。この
ことから、凹み幅率（ｔ）が０．５〜１．３の範囲で
は、素材中心部の偏析がピン内部に封入され、また、カ
ウンタウェイト部に欠肉も生じないものと推定される。
一方、図４に示すとおり、凹み高さ率（ｈ）が零の従来
荒地形状では、素材中心部の偏析がピン部表面に露出す
る偏析表出が見られ、凹み高さ率（ｈ）が０．６の荒地
形状では、ピン部表面への偏析表出が見られなかった
が、製品形状に疵が残り、カウンタウェイト部に欠肉が
発生した。このことから、凹み高さ率（ｈ）が０．２〜
０．５の範囲では、素材中心部の偏析がピン内部に封入
され、また、カウンタウェイト部に欠肉も生じないもの
と推定される。As shown in FIG. 3, in the conventional rough land shape having a dent width ratio (t) of zero and the rough land shape having a dent width ratio (t) of 0.42, segregation at the center of the material is exposed on the surface of the pin portion. In the rough land shape where the dent width ratio t was 1.3, no segregation expression on the surface of the pin portion was observed, but the product shape was flawed and the counterweight portion was underfilled. . From this, it is presumed that, when the dent width ratio (t) is in the range of 0.5 to 1.3, segregation at the center of the material is enclosed in the pin, and no underweight occurs in the counterweight portion. .
On the other hand, as shown in FIG. 4, in the conventional rough land shape having a dent height ratio (h) of zero, segregation at the center of the material is exposed on the pin surface, and the dent height ratio (h) is reduced. In the rough land shape of 0.6, no segregation appeared on the surface of the pin portion, but flaws remained in the product shape and underfill occurred in the counterweight portion. From this, the dent height ratio (h) is 0.2 to
In the range of 0.5, it is presumed that segregation at the central portion of the material is enclosed in the pin, and that the counterweight portion is not underfilled.
【００２１】実施例２ １１０ｍｍ角、長さ４２０ｍｍの鋼片を素材とし、４気
筒８枚カウンタウェイトのクランク軸を製造するに際
し、まず１２００℃に加熱された素材をロール工程で長
手方向に体積配分し、曲げ加工で幅方向に体積配分し
た。次に板状の突起を有する金型を用い、４つの全ての
ピン部分に表１に示す凹み高さ率、凹み幅率の凹み形状
Ａ〜Ｈの局所偏心を与えたのち、荒打ち、仕上打ちを行
った。また、比較の対象として従来の鍛造荒地形状にて
も同じ条件で鍛造した。凹み形状を有する荒地を鍛造し
た場合と従来の荒池を鍛造した場合の１ピン部の断面の
偏析の位置のメタルフローの観察結果を図２に示す。さ
らに、８つの凹み形状Ａ〜Ｈと偏析封入の可否、鍛造疵
と欠肉の発生有無を調査した。その結果を表２に示す。
なお、表２中の総合評価欄の○は良好、×は不良を示
す。Example 2 A steel piece having a size of 110 mm square and a length of 420 mm was used as a raw material. In manufacturing a crankshaft having eight cylinders and four cylinders, first, a raw material heated to 1200 ° C. was longitudinally volume-distributed in a rolling process. Then, the volume was distributed in the width direction by bending. Next, using a mold having plate-shaped projections, after giving local eccentricity of the concave shapes A to H of the concave height ratio and the concave width ratio shown in Table 1 to all four pin portions, roughing and finishing I made a beating. For comparison, a conventional forged rough ground shape was forged under the same conditions. FIG. 2 shows the observation results of the metal flow at the position of segregation in the cross section of the 1-pin portion when the rough land having the concave shape is forged and when the conventional rough pond is forged. Furthermore, eight concave shapes A to H, the possibility of segregation and sealing, and the occurrence of forging flaws and underfill were investigated. Table 2 shows the results.
In the comprehensive evaluation column in Table 2, ○ indicates good, and x indicates bad.
【００２２】[0022]
【表１】 [Table 1]
【００２３】[0023]
【表２】 [Table 2]
【００２４】図２（ｂ）に示すとおり、従来の荒地で
は、ピン部２１表面に鋼片中心部の偏析２２の露出によ
る表出部２３が見られたが、図２（ａ）に示すとおり、
本発明による荒地を用いた場合には、ピン部２１表面に
鋼片中心部の偏析２２は露出せずに内部に封入されて鍛
造できていた。なお、２４はカウンタウェイト部を示
す。また、表２に示すとおり、凹み幅率（ｔ）が１．３
５と本発明の範囲を外れている凹み形状Ａの荒地を用い
た場合には、ピン部分表面への鋼片中心部の偏析の封入
は可能であるが、疵ならびに欠肉の発生が見られた。凹
み幅率（ｔ）が０．４５と本発明の範囲を外れている凹
み形状Ｄの荒地を用いた場合は、疵ならびに欠肉の発生
が見られないが、ピン部分表面への鋼片中心部の偏析の
封入は不可能で、ピン部分表面に鋼片中心部の偏析の露
出による表出が見られた。凹み高さ率（ｈ）が０．５５
と本発明の範囲を外れている凹み形状Ｅの荒地を用いた
場合には、ピン部分表面への鋼片中心部の偏析の封入は
可能であるが、疵ならびに欠肉の発生が見られた。凹み
高さ率（ｈ）が０．１５と本発明の範囲を外れている凹
み形状Ｈの荒地を用いた場合には、疵ならびに欠肉の発
生が見られないが、ピン部分表面への鋼片中心部の偏析
の封入は不可能で、ピン部分表面に鋼片中心部の偏析の
露出による表出が見られた。凹み幅率（ｔ）、凹み高さ
率（ｈ）が共に本発明の範囲内である凹み形状Ｂ、Ｃ、
ＦおよびＧの荒地を用いた場合は、ピン部分表面への鋼
片中心部の偏析の封入は可能で、しかも、疵ならびに欠
肉の発生が見られず、観察結果は良好であった。さら
に、２〜４ピンについても同様の結果が得られた。As shown in FIG. 2 (b), in a conventional wasteland, exposed portions 23 due to the exposure of the segregation 22 at the center of the slab were seen on the surface of the pin portion 21, but as shown in FIG. 2 (a). ,
When the wasteland according to the present invention was used, the segregation 22 at the center of the slab was not exposed on the surface of the pin portion 21, but was sealed inside and forged. Reference numeral 24 denotes a counter weight unit. Further, as shown in Table 2, the dent width ratio (t) was 1.3.
In the case of using a rough land having a concave shape A out of the scope of the present invention, the segregation of the center portion of the steel slab can be included in the surface of the pin portion, but the generation of flaws and underfill is observed. Was. In the case of using a rough land having a dent shape D having a dent width ratio (t) of 0.45, which is out of the range of the present invention, no flaw or underfilling is observed, but the center of the billet on the surface of the pin portion is not observed. It was not possible to enclose segregation in the part, and the surface of the pin part was exposed due to the exposure of segregation in the center of the billet. The dent height ratio (h) is 0.55
In the case of using a rough land having a concave shape E which is out of the range of the present invention, it is possible to enclose segregation at the center of the steel slab on the surface of the pin portion, but occurrence of flaws and underfill was observed. . In the case of using a rough land having a dent shape H having a dent height ratio (h) of 0.15, which is out of the range of the present invention, no flaw or underfilling is observed, but steel on the surface of the pin portion is not found. It was not possible to enclose segregation at the center of the slab, and the pin surface was exposed due to exposure of segregation at the center of the slab. The dent shapes B and C whose dent width ratio (t) and dent height ratio (h) are both within the scope of the present invention.
When the rough land of F and G was used, the segregation of the center part of the steel slab was able to be enclosed in the surface of the pin portion, and further, no flaw or underfill was observed, and the observation result was good. Further, similar results were obtained for pins 2 to 4.
【００２５】[0025]
【発明の効果】この発明の請求項１のクランク軸鍛造荒
地は、局所的凹みを設けたことによって、クランク軸ピ
ン部表面への素材中心部の不純物偏析部の露出による表
出を抑制でき、ピン部の疲労強度の低下を抑制できると
共に、クランク軸の品質を向上させることができる。According to the first aspect of the present invention, the rough forged crankshaft according to the first aspect of the present invention is provided with the local recess, so that the surface of the crankshaft pin portion can be prevented from being exposed to the impurity segregated portion at the center portion of the material, A decrease in the fatigue strength of the pin portion can be suppressed, and the quality of the crankshaft can be improved.
【００２６】この発明の請求項２のクランク軸鍛造荒地
は、凹み幅率ｔ：０．５〜１．３、凹み高さ率Ｈ：０．
２〜０．５の局所的凹みを設けたことによって、クラン
ク軸ピン部表面への素材中心部の不純物偏析部の露出に
よる表出を防止でき、ピン部の疲労強度の低下を防止で
きると共に、クランク軸の品質を向上させることができ
る。According to the second aspect of the present invention, the forged crankshaft has a recess width ratio t: 0.5 to 1.3 and a recess height ratio H: 0.
By providing the local recesses of 2 to 0.5, it is possible to prevent the surface of the crankshaft pin portion from being exposed due to the exposure of the impurity segregation portion at the center of the material, thereby preventing the fatigue strength of the pin portion from decreasing, The quality of the crankshaft can be improved.
【図１】この発明のクランク軸鍛造荒地の形状説明図
で、（ａ）図はこの発明の荒地形状の側面図、（ｂ）図
は（ａ）図の鍛造荒地を荒型、仕上型で型打ちして得た
４気筒８枚カウンタウェイトのクランク軸、（ｃ）図は
従来の荒地形状の１例の側面図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a shape of a forged rough land of a crankshaft of the present invention. FIG. 1 (a) is a side view of the rough land shape of the present invention, and FIG. 1 (b) is a rough type and a finished type. The crankshaft of a four-cylinder, eight-cylinder counterweight obtained by stamping, FIG. 3 (c) is a side view of one example of a conventional rough land shape.
【図２】素材中心部の不純物偏析部のピン部への偏析位
置の断面を示すもので、（ａ）図は従来の鍛造荒地を用
いた場合、（ｂ）図はこの発明の鍛造荒地を用いた場合
を示す。FIG. 2 shows a cross section of a segregated position of an impurity segregated portion in the center of a material on a pin portion. FIG. 2 (a) shows a case where a conventional forged wasteland is used, and FIG. 2 (b) shows a forged wasteland of the present invention. Shows the case when used.
【図３】凹み幅率と型打後の偏析位置と製品性状との関
係を示すグラフである。FIG. 3 is a graph showing a relationship between a dent width ratio, a segregation position after stamping, and product properties.
【図４】凹み高さ率と型打後の偏析位置と製品性状との
関係を示すグラフである。FIG. 4 is a graph showing a relationship between a dent height ratio, a segregation position after stamping, and product properties.
【図５】一般的なクランク軸鍛造の順序を示すもので、
（ａ）図は素材、（ｂ）図はロール加工後の段付き軸、
（ｃ）図は曲げ加工後の鍛造荒地、（ｄ）図は型打後の
クランク軸の説明図である。FIG. 5 shows a general crankshaft forging sequence.
(A) Figure is a material, (b) is a stepped shaft after roll processing,
(C) is a forged wasteland after bending, and (d) is an explanatory view of a crankshaft after stamping.
１、５４ クランク軸 ２ａ〜２ｄ ピン ３ａ〜３ｄ アーム ４ａ〜４ｄ 凹み ５、１１ 鍛造荒地 ２１、５６ ピン部 ２２ 偏析 ２３ 表出部 ２４ カウンタウェイト部 ５１ 鋼片 ５２ 段付き軸 ５３ 曲げ軸 ５５ 偏析部 1,54 Crankshaft 2a-2d Pin 3a-3d Arm 4a-4d Depression 5,11 Forged Wasteland 21,56 Pin Part 22 Segregation 23 Exposure Part 24 Counter Weight Part 51 Slab 52 Stepped Shaft 53 Bending Axis 55 Segregation Part
Claims (2)
て、カウンタウェイト間のピンを形成する部位に、鍛造
により形成されるカウンタウェイトからピン側に向かう
局所的凹みを有することを特徴とする鍛造荒地形状。1. A forged wasteland for the manufacture of a crankshaft, wherein a portion between the counterweights where a pin is formed has a local recess from the counterweight formed by forging toward the pins. shape.
て、カウンタウェイト間のピンを形成する部位に、鍛造
により形成されるカウンタウェイトからピン側に向かう
下記（１）〜（２）式により求めた凹み高さ率（ｈ）が
０．２〜０．５、凹み幅率（ｔ）が０．５〜１．３の局
所的凹みを有することを特徴とする鍛造荒地形状。 凹み高さ率（ｈ）＝（ＨＳ−ＨＥ）／ＨＳ……（１）式 凹み幅率（ｔ）＝ＭＷ／ＣＷ……（２）式 ただし、ＨＳ： 従来荒地高さ、ＨＥ： 本発明荒地高
さ、ＭＷ： 凹み幅、ＣＷ：カウンタウェイト間隔であ
る。2. In a forged wasteland for manufacturing a crankshaft, a portion where a pin is formed between counterweights is determined by the following formulas (1) and (2) from the counterweight formed by forging toward the pins. A forged rough land shape having a local dent having a dent height ratio (h) of 0.2 to 0.5 and a dent width ratio (t) of 0.5 to 1.3. Depression height ratio (h) = (HS−HE) / HS Expression (1) Expression Width ratio (t) = MW / CW Expression (2) where HS: Conventional wasteland height, HE: The present invention Wasteland height, MW: recess width, CW: counter weight interval.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20664796A JPH1029033A (en) | 1996-07-16 | 1996-07-16 | Rough-forging shape of crank shaft |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20664796A JPH1029033A (en) | 1996-07-16 | 1996-07-16 | Rough-forging shape of crank shaft |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1029033A true JPH1029033A (en) | 1998-02-03 |
Family
ID=16526821
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20664796A Pending JPH1029033A (en) | 1996-07-16 | 1996-07-16 | Rough-forging shape of crank shaft |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1029033A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101467041B1 (en) * | 2012-09-27 | 2014-12-02 | 현대제철 주식회사 | Manufacturing method of crank shaft |
| CN104942194A (en) * | 2014-03-25 | 2015-09-30 | 株式会社神户制钢所 | Method for forging a crank throw, method for manufacturing a crank throw and crank throw |
| CN105363990A (en) * | 2015-11-27 | 2016-03-02 | 昆山惠众机电有限公司 | Long-rod integrated transmission shaft forging technology |
| CN107405678A (en) * | 2015-03-24 | 2017-11-28 | 新日铁住金株式会社 | The manufacture method of crankshaft forging |
-
1996
- 1996-07-16 JP JP20664796A patent/JPH1029033A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101467041B1 (en) * | 2012-09-27 | 2014-12-02 | 현대제철 주식회사 | Manufacturing method of crank shaft |
| CN104942194A (en) * | 2014-03-25 | 2015-09-30 | 株式会社神户制钢所 | Method for forging a crank throw, method for manufacturing a crank throw and crank throw |
| CN107405678A (en) * | 2015-03-24 | 2017-11-28 | 新日铁住金株式会社 | The manufacture method of crankshaft forging |
| CN105363990A (en) * | 2015-11-27 | 2016-03-02 | 昆山惠众机电有限公司 | Long-rod integrated transmission shaft forging technology |
| CN105363990B (en) * | 2015-11-27 | 2017-04-19 | 昆山惠众机电有限公司 | Long-rod integrated transmission shaft forging technology |
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