JP2006312978A - Con'rod manufacturing method - Google Patents

Con'rod manufacturing method Download PDF

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Publication number
JP2006312978A
JP2006312978A JP2005136159A JP2005136159A JP2006312978A JP 2006312978 A JP2006312978 A JP 2006312978A JP 2005136159 A JP2005136159 A JP 2005136159A JP 2005136159 A JP2005136159 A JP 2005136159A JP 2006312978 A JP2006312978 A JP 2006312978A
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Prior art keywords
burr
die
connecting rod
column
column portion
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Inventor
Satoshi Kamo
聡 加茂
Hiroyuki Mizuno
浩行 水野
Hirokatsu Hayakawa
弘勝 早川
Kinsei Kino
欣成 嬉野
Motohide Mori
元秀 森
Takashi Fujita
崇史 藤田
Hirotada Takada
啓督 高田
Toshizo Tarui
敏三 樽井
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Nippon Steel Corp
Toyota Motor Corp
Aichi Steel Corp
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Nippon Steel Corp
Toyota Motor Corp
Aichi Steel Corp
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Priority to JP2005136159A priority Critical patent/JP2006312978A/en
Publication of JP2006312978A publication Critical patent/JP2006312978A/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21JFORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J5/00Methods for forging, hammering, or pressing; Special equipment or accessories therefor
    • B21J5/02Die forging; Trimming by making use of special dies ; Punching during forging
    • B21J5/027Trimming

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
  • Forging (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a con'rod superior in symmetric property of cross-sectional shape of a column portion and having high buckling strength. <P>SOLUTION: This method of manufacturing the con'rod includes a hot forging process, a trimming process and a cold coining process. In the trimming process, a trimming die 5 having a trimming hole 50 and a burr cutting blade 51 mounted around the hole, is used, the con'rod is inserted into the trimming hole 50 of the trimming die 5 so that burr 2 is brought into contact with the burr cutting blade 51, a restraint die 6 is brought into contact with at least the column portion 13 of the con'rod penetrated through and projecting from the trimming hole 50 for restricting ribs 131 at both sides of the column portion 13 so that they are prevented from being deformed in the opening direction, and the con'rod is pressed by a pressing die 4 to press the burr 2 to the burr cutting blade 51 to cut the burr 2 while keeping the restraining state of the column portion 13 by the restraint die 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、座屈強度の低下を抑制できるコンロッドの製造方法に関する。   The present invention relates to a connecting rod manufacturing method capable of suppressing a decrease in buckling strength.

自動車等に用いられるエンジンの部品の一つであるコンロッドは、熱間鍛造によって製造される場合が多い。一般的な製造方法としては、熱間鍛造工程、バリ抜き工程、冷間コイニング工程を行う方法がある(例えば、特許文献1)。
ところで、上記コンロッドは、周知のように大端部と小端部とこれらを繋ぐコラム部とを有するものであり、上記コラム部は、両側に配されたリブと、これらを繋ぐ幹部とよりなる断面略H型とすることが通常である。そして、コンロッドは、シリンダー内の爆発力をコンロッドの小端部側に固定されたピストンで受けた際の圧縮力に耐える必要があるため、コラム部の座屈強度を高めることが軽量化を可能にするために不可欠となる。そのため、座屈強度を向上するための研究が盛んに進められている。
A connecting rod, which is one of engine parts used in automobiles, is often manufactured by hot forging. As a general manufacturing method, there is a method of performing a hot forging process, a deburring process, and a cold coining process (for example, Patent Document 1).
By the way, the connecting rod has a large end portion, a small end portion, and a column portion connecting these, as is well known, and the column portion includes ribs arranged on both sides and a trunk portion connecting them. Usually, the cross section is substantially H-shaped. And the connecting rod needs to withstand the compressive force when the explosive force in the cylinder is received by the piston fixed to the small end side of the connecting rod, so it is possible to reduce the weight by increasing the buckling strength of the column part To become indispensable. Therefore, research for improving the buckling strength has been actively promoted.

また、座屈強度を高める研究が盛んに行われている一方で、製造上座屈強度が低下する要因となる問題も残っている。すなわち、実際の製造では、コラム部の断面形状が完全に対称となるコンロッドを製造することが難しいという問題である。
コラム部の断面形状が表裏対称でない場合、たとえばH型の両側のリブが平行でなく斜めに傾いている場合には、H断面の上部と下部で圧縮力に対する抵抗力に差異が生じてしまうため、どうしてもコラム部に曲げ歪みが生じてしまうことになる。したがって、この曲げ歪みが一定量を超えて大きくなると当然座屈現象が生じることとなり、完全対称の場合に比較して、曲げ歪みが大きく生じる分だけ座屈強度がより大きく低下してしまうことになるのである。上記の一般的な製造方法において製造したコンロッドは、コラム部に上記のような変形が生じる場合が多く、その分全体の剛性向上のために肉厚化するなどの対応策が必要となり、軽量化の妨げの1つともなっている。
In addition, while researches for increasing the buckling strength have been actively conducted, there remains a problem that causes a reduction in the buckling strength in manufacturing. In other words, in actual manufacturing, it is difficult to manufacture a connecting rod in which the cross-sectional shape of the column portion is completely symmetric.
When the cross-sectional shape of the column part is not symmetrical, for example, when the ribs on both sides of the H-shaped are not parallel but inclined, there is a difference in resistance to compressive force between the upper and lower parts of the H-section. Anyway, bending distortion will occur in the column part. Therefore, if this bending strain increases beyond a certain amount, a buckling phenomenon will naturally occur, and the buckling strength will be greatly reduced by the amount of bending strain compared to the case of perfect symmetry. It becomes. The connecting rod manufactured in the above general manufacturing method often undergoes deformation as described above in the column part, and accordingly, measures such as increasing the wall thickness are necessary to improve the overall rigidity. It is one of the obstacles.

特開2003−147434号公報JP 2003-147434 A

本発明は、かかる従来の問題点に鑑みてなされたもので、コラム部の断面形状の対称性に優れ、座屈強度の高いコンロッドを得ることができる製造方法を提供しようとするものである。   The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a manufacturing method capable of obtaining a connecting rod having excellent symmetry of the cross-sectional shape of the column portion and high buckling strength.

本発明は、素材に熱間鍛造を施して、大端部と小端部とこれらを繋ぐ断面略H型のコラム部とを有すると共に外周部にバリを備えたコンロッドを成形する熱間鍛造工程と、上記コンロッドの外周部に生じた上記バリを除去するバリ抜き工程と、上記大端部、上記小端部および上記コラム部に冷間コイニングを施す冷間コイニング工程とを含むコンロッドの製造方法において、
上記バリ抜き工程においては、抜き穴を有すると共にその周囲にバリ切断刃を備えた抜き型を用い、該抜き型の上記抜き穴に上記コンロッドを挿入して上記バリを上記バリ切断刃に当接させ、
上記抜き穴を貫通突出した上記コンロッドの少なくとも上記コラム部に対し、該コラム部の両側のリブが開く方向に変形することを阻止するように拘束する拘束型を当接させ、
該拘束型による上記コラム部の拘束状態を維持したまま、加圧型によって上記コンロッドを押圧して上記バリを上記バリ切断刃に押しつけることにより、上記バリの切除を行うことを特徴とするコンロッドの製造方法にある(請求項1)。
The present invention provides a hot forging process in which a hot forging process is performed on a material to form a connecting rod having a large end portion, a small end portion, and a column portion having a substantially H-shaped cross section connecting the large end portion and a burr on the outer peripheral portion. And a deburring step for removing the burrs generated on the outer periphery of the connecting rod, and a cold coining step for performing cold coining on the large end portion, the small end portion and the column portion. In
In the deburring step, a punching die having a punching hole and a burr cutting blade around it is used, and the connecting rod is inserted into the punching hole of the punching die so that the burr is brought into contact with the burr cutting blade. Let
A constraining die that is constrained so as to prevent the ribs on both sides of the column part from being deformed in an opening direction is brought into contact with at least the column part of the connecting rod protruding through the punched hole;
Manufacturing the connecting rod characterized in that the burr is cut off by pressing the connecting rod by a pressure die and pressing the burr against the burr cutting blade while maintaining the constrained state of the column portion by the restricting die. There is a method (claim 1).

本発明の製造方法において注目すべき点は、上記バリ抜き工程において、上記拘束型を用い、上記コラム部の上記変形を阻止するための上記拘束型による拘束状態を維持したままバリの切除を行うことである。これにより、最終的に、コラム部の断面形状の対称性に優れ、座屈強度の高いコンロッドを得ることができる。   What should be noted in the manufacturing method of the present invention is that, in the deburring step, the constraining mold is used, and the burr is removed while maintaining the constraining state by the constraining mold for preventing the deformation of the column part. That is. Thereby, finally, a connecting rod having excellent symmetry of the cross-sectional shape of the column portion and high buckling strength can be obtained.

すなわち、上記バリ抜き工程では、上記拘束型によって両側のリブが開かないように拘束した状態で上記バリを上記抜き型のバリ切断刃に押しつける。このとき、上記拘束型を用いない場合には、コラム部がバリ抜き時の剪断力によって引っ張られて、両側のリブが「ハ」字状に開くように変形する可能性がある。これに対し、上記拘束型によってコラム部を拘束している場合には、上記の「ハ」字状への変形を抑制することができ、バリ抜き工程直後におけるコラム部の変形を皆無に近くまたは従来よりも小さくすることができる。   That is, in the deburring step, the burr is pressed against the burr cutting blade of the punching die in a state of being restrained so that the ribs on both sides are not opened by the restraining die. At this time, when the constraint type is not used, there is a possibility that the column part is pulled by a shearing force at the time of deburring and the ribs on both sides are deformed so as to open in a “C” shape. On the other hand, when the column portion is constrained by the constraining die, it is possible to suppress the deformation to the “C” shape, and there is almost no deformation of the column portion immediately after the deburring process or It can be made smaller than before.

上記バリ抜き工程の後に行う上記冷間コイニング工程では、上記コラム部を上記バリ抜きの方向と同じ方向に圧縮する工程である。そのため、コラム部が冷間コイニング工程を実施する前に「ハ」字状に変形していた場合には、冷間コイニングの際の圧縮力が、上記変形を増長させる方向に働き、より大きな変形を引き起こしてしまう。また、これは、冷間コイニング前の「ハ」字状への変形が大きいほど顕著となる。このような変形の増長をも、上記バリ抜き工程での変形抑制効果によって抑制することができる。
そして、これにより、上述したごとく、コラム部の断面形状の対称性に優れ、座屈強度の高いコンロッドを得ることができるのである。
The cold coining step performed after the deburring step is a step of compressing the column portion in the same direction as the deburring direction. Therefore, if the column part is deformed in a “C” shape before the cold coining process is performed, the compressive force during cold coining acts in the direction of increasing the above deformation, resulting in greater deformation. Will cause. In addition, this becomes more prominent as the deformation to the “C” shape before cold coining is larger. Such an increase in deformation can also be suppressed by the deformation suppressing effect in the deburring step.
As a result, as described above, a connecting rod having excellent symmetry of the cross-sectional shape of the column portion and high buckling strength can be obtained.

本発明においては、上記拘束型は、上記抜き型から突出した上記コラム部の両側の上記リブの先端部を収容する収容凹部を備えていることが好ましい(請求項2)。この場合には、上記収容凹部に上記コラム部の先端部を収めておくことによって、その拘束を確実に行うことができる。なお、上記収容凹部としては、H型の両側のリブの先端部2つに対してそれぞれ対応するよう2つ設けることが、その変形防止効果が最も高く好ましい。一方、両側のリブの先端部2つをまとめて収容し、少なくともその外方部からの拘束効果が得られる1つの収容凹部とすることも可能である。   In the present invention, it is preferable that the constraining die includes a housing recess for housing the tip portions of the ribs on both sides of the column portion protruding from the punching die. In this case, the restraint can be reliably performed by storing the tip of the column part in the accommodating recess. In addition, it is preferable to provide two accommodating recesses so as to correspond to the two tip portions of the ribs on both sides of the H-shaped because the deformation preventing effect is the highest. On the other hand, it is also possible to house the two tip portions of the ribs on both sides together to form one housing recess that can at least obtain a restraining effect from the outer portion.

なお、上記収容凹部を設けない拘束方法として、非常に摩擦係数の高い表面を上記拘束型に設けることも可能である。その場合には、十分な摩擦力を確保するために十分な当接力を維持し続けるよう制御することが重要となる。そのため、上記収容凹部に頼る方が製造上合理的である。   In addition, as a restraining method that does not provide the housing recess, a surface having a very high friction coefficient can be provided in the restraining mold. In that case, it is important to control to maintain a sufficient contact force in order to ensure a sufficient frictional force. For this reason, it is more reasonable in manufacturing to rely on the housing recess.

また、上記熱間鍛造工程および上記冷間コイニング工程としては、従来一般的に行われている方法を採用することができる。また、冷間コイニング工程の前には、ショットブラスト工程を追加することもできる。
また、上記素材としては、コンロッドとして使用できるものであれば特に限定する必要はない。
In addition, as the hot forging process and the cold coining process, a conventionally performed method can be employed. A shot blasting process can be added before the cold coining process.
In addition, the material is not particularly limited as long as it can be used as a connecting rod.

(実施例1)
本発明の実施例に係るコンロッドの製造方法につき、図1〜図6を用いて説明する。
本例では、図1に示すごとく、大端部11と小端部12とこれらを繋ぐ断面略H型のコラム部13とを有するコンロッド1を製造する。コラム部13は、同図に示すごとく、両側に配されたリブ131と、これらを繋ぐ幹部130とより構成され、上記のごとく、なる断面略H型である。
本例の製造方法は、図2に示すごとく、熱間鍛造工程S1、バリ抜き工程S2、ショットブラスト工程S3、及び冷間コイニング工程S4を含むものである。なお、ショットブラスト工程S3は、省略することも可能である。また、同図に示すごとく、冷間コイニング工程S4の後には、必要に応じて、ショットピーニング工程S5と機械加工工程S6を追加する場合もある。
Example 1
A method for manufacturing a connecting rod according to an embodiment of the present invention will be described with reference to FIGS.
In this example, as shown in FIG. 1, a connecting rod 1 having a large end portion 11, a small end portion 12, and a column portion 13 having a substantially H-shaped cross section connecting them is manufactured. As shown in the figure, the column portion 13 is composed of ribs 131 arranged on both sides and a trunk portion 130 connecting them, and has a substantially H-shaped cross section as described above.
As shown in FIG. 2, the manufacturing method of this example includes a hot forging step S1, a deburring step S2, a shot blasting step S3, and a cold coining step S4. Note that the shot blasting step S3 can be omitted. Further, as shown in the figure, after the cold coining step S4, a shot peening step S5 and a machining step S6 may be added as necessary.

まず、上記熱間鍛造工程S1は、素材に熱間鍛造を施して、大端部11と小端部12とこれらを繋ぐ断面略H型のコラム部13とを有するコンロッド1を成形する周知の工程である。実際には、図3に示すごとく、コンロッド1の外周に、一対の鍛造型の間隙に据え込まれて形成されるバリ2が生じている。そのため、次のバリ抜き工程S2を実施する。   First, the hot forging step S1 is a well-known process for forming a connecting rod 1 having a large end portion 11, a small end portion 12, and a column portion 13 having a substantially H-shaped cross section connecting them by hot forging the material. It is a process. Actually, as shown in FIG. 3, a burr 2 formed by being installed in the gap between the pair of forging dies is generated on the outer periphery of the connecting rod 1. Therefore, the next deburring step S2 is performed.

本例のバリ抜き工程S2では、図4(a)に示すごとく、抜き穴50を有すると共にその周囲にバリ切断刃51を備えた抜き型5を用い、抜き型5の抜き穴50にコンロッド1を挿入してバリ2をバリ切断刃51に当接させる。そして、抜き穴50を貫通突出したコンロッド1のコラム部13に対し、その幅方向の変形を阻止するように拘束する拘束型6を当接させる。   In the deburring step S2 of this example, as shown in FIG. 4A, a cutting die 5 having a punching hole 50 and provided with a burr cutting blade 51 around it is used, and the connecting rod 1 is inserted into the punching hole 50 of the punching die 5. Is inserted to bring the burr 2 into contact with the burr cutting blade 51. Then, the constraining die 6 that constrains the column portion 13 of the connecting rod 1 protruding through the punched hole 50 so as to prevent deformation in the width direction is brought into contact.

同図に示すごとく、本例の拘束型6は、抜き型5から突出したコラム部13の両側のリブ131の先端部132をそれぞれ収容する2つの収容凹部61を備えている。各収容凹部61は、深さDが1mmとなるように設定してあり、図4(b)に示すごとく、コラム部131の先端部132の外側面133及び内側面134に対し、凹部外側面613と凹部内側面614とが当接するようにしてある。なお、この側面の当接関係は、あらかじめ許容交差分だけクリアランスを設けておき、変形が起こった際に実際に当接するように設定することも可能である。   As shown in the figure, the constraining die 6 of this example includes two housing recesses 61 for housing the tip portions 132 of the ribs 131 on both sides of the column portion 13 protruding from the punching die 5. Each receiving recess 61 is set to have a depth D of 1 mm. As shown in FIG. 4B, the recess recess outer surface with respect to the outer surface 133 and the inner surface 134 of the tip portion 132 of the column portion 131. 613 and the inner surface 614 of the recess are in contact with each other. The contact relationship between the side surfaces may be set so that clearance is provided in advance for an allowable intersection, and the contact is actually made when deformation occurs.

そして、図4(b)に示すごとく、拘束型6によるコラム部13の拘束状態を維持したまま、加圧型4によってコンロッド1を押圧する。なお、加圧型4は、バリ2を押さえるバリ押さえ部41をスプリング42を介して有している。そのため、コンロッド1を押圧する際には、上記バリ押さえ部41によってバリ2を保持することができる。そして、この押圧時には、拘束型6は図示しないバネのバネ力によって必要とする拘束力を保持したまま、加圧型4の下方への移動と共に下方へ移動する。それと共に、バリ2が固定されているバリ切断刃51に押しつけられた際にも、コラム部13全体が下方の拘束型6へ押しつけられることとなるため、その結果、コラム部が拘束された状態のままバリ2が切除可能となる。
つまり、本例では、上記のごとく拘束型6によるコラム部13の拘束状態を維持した状態でバリ2の切除を行うので、コラム部13における両側のリブ131が「ハ」字状に開かれるように変形することを抑制することができる。
Then, as shown in FIG. 4B, the connecting rod 1 is pressed by the pressurization die 4 while maintaining the restraint state of the column portion 13 by the restraint die 6. Note that the pressing die 4 has a burr pressing portion 41 for pressing the burr 2 via a spring 42. Therefore, when the connecting rod 1 is pressed, the burr 2 can be held by the burr pressing portion 41. At the time of pressing, the restraint die 6 moves downward together with the downward movement of the pressurizing die 4 while holding the necessary restraint force by the spring force of a spring (not shown). At the same time, when the burrs 2 are pressed against the burr cutting blade 51 to which the burrs 2 are fixed, the entire column portion 13 is pressed against the lower restraining die 6, so that the column portion is constrained. The burr 2 can be excised.
That is, in this example, since the burr 2 is removed while maintaining the constrained state of the column portion 13 by the constraining die 6 as described above, the ribs 131 on both sides of the column portion 13 are opened in a “C” shape. Can be prevented from being deformed.

このバリ抜き工程S2を行った後、本例では酸化スケールを除去するためのショットブラスト工程S3を行い、その後、冷間コイニング工程S4を実施する。
冷間コイニング工程S4では、図5、図6に示すごとく、上下一対のコイニング型71または72によって、コンロッド1の大端部11、小端部12およびコラム部13を挟持して圧縮荷重を加える。コイニング型としては、図5に示すごとく、コラム部13に関してはその長手方向中央部のみに圧縮荷重を加えるコイニング型71と、図6に示すごとく、コラム部13の長手方向全長に圧縮荷重を加えるコイニング型72とがある。
After performing this deburring step S2, in this example, a shot blasting step S3 for removing oxide scale is performed, and then a cold coining step S4 is performed.
In the cold coining step S4, as shown in FIGS. 5 and 6, a compression load is applied by sandwiching the large end portion 11, the small end portion 12 and the column portion 13 of the connecting rod 1 by a pair of upper and lower coining dies 71 or 72. . As the coining type, as shown in FIG. 5, with respect to the column portion 13, a coining die 71 that applies a compressive load only to the central portion in the longitudinal direction, and a compressive load applied to the entire length in the longitudinal direction of the column portion 13 as shown in FIG. 6. There is a coining mold 72.

このような製造方法を採用することにより、本例で得られるコンロッド1は、従来よりもコラム部13の変形が少なく、座屈強度も従来よりも向上したものとなる。
すなわち、本例では、上記のような拘束型6を用いることにより、バリ抜き工程S2においてコラム部13がバリ抜き時の剪断力によって引っ張られて、両側のリブ131が「ハ」字状に変形することを十分に抑制することができるのである。
そして、バリ抜き工程S2での変形の抑制によって、その後の冷間コイニング工程S4における圧縮力による変形の増長も抑制することができる。
それ故、本例の製造方法では、コラム部13の断面形状の対称性に優れ、座屈強度の高いコンロッド1を得ることができるのである。
By adopting such a manufacturing method, the connecting rod 1 obtained in this example has less deformation of the column portion 13 than the conventional one, and the buckling strength is improved as compared with the conventional one.
That is, in this example, by using the restraint die 6 as described above, the column portion 13 is pulled by the shearing force at the time of deburring in the deburring step S2, and the ribs 131 on both sides are deformed into a “C” shape. This can be sufficiently suppressed.
Then, by suppressing the deformation in the deburring step S2, it is possible to suppress the increase in deformation due to the compressive force in the subsequent cold coining step S4.
Therefore, in the manufacturing method of this example, it is possible to obtain the connecting rod 1 having excellent symmetry of the cross-sectional shape of the column portion 13 and high buckling strength.

(実施例2)
本例では、実施例1の作用効果を明確にするために、複数種類の条件(試験No.1〜9)によってコンロッドを作製し、その変形状態および座屈強度を評価した。
本例では、素材として、S55C(0.55%C−0.25%Si−0.75%Mn)鋼を用い、基本的に上述した実施例1と同様の製造工程を実施した(図2)。
(Example 2)
In this example, in order to clarify the operational effects of Example 1, connecting rods were produced under a plurality of types of conditions (test Nos. 1 to 9), and the deformation state and buckling strength were evaluated.
In this example, S55C (0.55% C-0.25% Si-0.75% Mn) steel was used as a material, and the same manufacturing process as that of Example 1 described above was performed (FIG. 2). ).

熱間鍛造工程S1は、上記素材を1250℃に加熱し、熱間鍛造を施して大端部11、小端部12、及びコラム部13を形成した。
次いで、バリ抜き工程S2は、3種類の条件で行った。本発明の実施例としては、前述した図4に示すごとく、2つの収容凹部61を有しその深さDを1mmとしたタイプの第1の拘束型6を用いた試験(No.1〜3)と、同様に2つの収容凹部61を有するがその深さDを0.5mmとしたタイプの第2の拘束型6を用いた試験(No.4〜6)を行った。
Hot forging process S1 heated the said raw material to 1250 degreeC, gave hot end forging, and formed the large end part 11, the small end part 12, and the column part 13. As shown in FIG.
Next, the deburring step S2 was performed under three conditions. As an example of the present invention, as shown in FIG. 4 described above, a test (No. 1 to 3) using the first constraining die 6 of the type having two receiving recesses 61 and having a depth D of 1 mm. ) And a test (No. 4 to 6) using a second constraining die 6 of the type having two housing recesses 61 but having a depth D of 0.5 mm.

また、図7(a)(b)に示すごとく、比較例として、拘束型を全く用いない試験(No.7〜9)も行った。すなわち、試験No.7〜9では、同図に示すごとく、上記バリ抜き工程S2においては、抜き穴50を有すると共にその周囲にバリ切断刃51を備えた抜き型5を用い、抜き型5の抜き穴50にコンロッド1を挿入してバリ2をバリ切断刃51に当接させ、拘束型を用いることなく、加圧型4によってコンロッド1を押圧してバリ2をバリ切断刃51に押しつけることにより、バリ2の切除を行った。   Moreover, as shown to Fig.7 (a) (b), the test (No. 7-9) which does not use a constraint type | mold at all was also done as a comparative example. That is, test no. 7 to 9, as shown in the figure, in the deburring step S <b> 2, a punching die 5 having a punching hole 50 and having a burr cutting blade 51 around it is used, and a connecting rod is inserted into the punching hole 50 of the punching die 5. 1 is inserted, the burr 2 is brought into contact with the burr cutting blade 51, and the burr 2 is excised by pressing the connecting rod 1 with the pressure die 4 and pressing the burr 2 against the burr cutting blade 51 without using a constraining die. Went.

バリ抜き工程S2の後にはショットブラスト工程S3を実施し、その後に冷間コイニング工程S4を実施した。この冷間コイニング工程S4では、3種類の条件を採用した。第1の条件は、コイニング型71(図5)を用いて、加工率を5%とする条件である(試験No.1、4、7)。この条件は、通常のコイニング方法であるので、後述する表1では加工種類を「通常」と示した。第2の条件は、コイニング型72(図6)を用いて、加工率を15%とする条件である(試験No.2、5、8)。第3の条件は、コイニング型72(図6)を用いて、加工率を25%とする条件である(試験No.3、6、9)。この第2の条件及び第3の条件は、コイニング加工によってコラム部の強度を高めることができるため、後述する表1では、加工種類を「コラム強化」と示した。なお、加工率は、リブ高さの減少率、すなわち、(1−コイニング後リブ高さ/コイニング前のリブ高さ)×100(%)によって定めることができる。   After the deburring step S2, a shot blasting step S3 was performed, followed by a cold coining step S4. In this cold coining step S4, three kinds of conditions were adopted. The first condition is a condition in which the coining die 71 (FIG. 5) is used and the processing rate is 5% (Test Nos. 1, 4, and 7). Since this condition is a normal coining method, the processing type is indicated as “normal” in Table 1 described later. The second condition is a condition in which the coining die 72 (FIG. 6) is used and the processing rate is set to 15% (Test Nos. 2, 5, and 8). The third condition is a condition in which the coining die 72 (FIG. 6) is used and the processing rate is 25% (test Nos. 3, 6, and 9). In the second condition and the third condition, the strength of the column portion can be increased by coining, so in Table 1 described later, the processing type is indicated as “column strengthening”. The processing rate can be determined by a reduction rate of the rib height, that is, (1−ribing height after coining / rib height before coining) × 100 (%).

得られた9種類のコンロッドについて、まず、その変形状態を評価した。変形状態は、図8に示すごとく、「ハ」字状となった状態を、両側のリブ131の傾きを示す中心線139のなす角度αによって評価することとした。
また、得られた9種類のコンロッドについて、座屈試験(圧縮試験)を行い、0.2%耐力を測定した。
これらの結果を表1に示す。
For the nine types of connecting rods obtained, the deformation state was first evaluated. As shown in FIG. 8, the deformed state is evaluated by the angle α formed by the center line 139 indicating the inclination of the ribs 131 on both sides of the “C” -shaped state.
Moreover, about 9 types of obtained connecting rods, the buckling test (compression test) was done and 0.2% yield strength was measured.
These results are shown in Table 1.

Figure 2006312978
Figure 2006312978

得られた結果は、冷間コイニングの条件ごとに評価することができる。すなわち、表1より知られるごとく、冷間加工率5%の場合には、本発明の例のうち、第1の拘束型を用いたもの(試験No.1)が、変形量(ハの字角度)が一番小さく、0.2%耐力が一番高かった。これに対し、比較例(試験No.7)の場合は、変形量(ハの字角度)が一番大きく、0.2%耐力も一番低かった。本発明の例のうち、第2の拘束型を用いたもの(試験No.4)は、上記2つの結果の中間の特性を示した。
また、この傾向は、冷間加工率が15%の場合の比較(試験No.2、5、8)と、冷間加工率が25%の場合の比較(試験No.3、6、9)においても同様である。
The obtained results can be evaluated for each cold coining condition. That is, as is known from Table 1, when the cold working rate is 5%, among the examples of the present invention, the one using the first constraining die (test No. 1) is deformed (shaped C). Angle) was the smallest and 0.2% yield strength was the highest. On the other hand, in the case of the comparative example (Test No. 7), the deformation amount (C-shaped angle) was the largest and the 0.2% yield strength was the lowest. Among the examples of the present invention, the one using the second restraint type (Test No. 4) exhibited an intermediate characteristic between the above two results.
Moreover, this tendency is the comparison when the cold working rate is 15% (test No. 2, 5, 8) and the comparison when the cold working rate is 25% (test No. 3, 6, 9). The same applies to.

以上の結果から、従来の製造方法(試験No.7〜9)に比べて、本発明の拘束型を用いたバリ抜き工程S2を実施した製造方法(試験No.1〜6)は、冷間加工率ごとに評価すると、従来よりも変形量を抑制することができ、座屈強度を向上させることができることがわかる。また、試験No.1〜3と試験No.4〜5との比較から、拘束型の収容凹部は、その深さが深い方が拘束力が高くなり、より良好な結果が得られることがわかる。ただし、その深さの最適な寸法は、コンロッドの寸法サイズ等によって変化することが考えられ、実験によって最適化することが好ましいと考えられる。   From the above results, the manufacturing method (Test Nos. 1 to 6) in which the deburring step S2 using the constraining die of the present invention was performed in comparison with the conventional manufacturing method (Test Nos. 7 to 9) was cold. If it evaluates for every processing rate, it turns out that a deformation amount can be suppressed rather than before and buckling strength can be improved. In addition, Test No. 1 to 3 and test no. From the comparison with 4 to 5, it can be seen that the constraining-type accommodation recess has a deeper depth and a higher restraining force, and a better result can be obtained. However, it is conceivable that the optimum dimension of the depth varies depending on the dimensional size of the connecting rod and the like, and it is preferable to optimize by the experiment.

実施例1における、最終製品としてのコンロッドの形状を示す(a)平面図、(b)側面図、(c)A−A線矢視断面拡大図。The (a) top view which shows the shape of the connecting rod as a final product in Example 1, (b) Side view, (c) AA AA arrow expanded sectional view. 実施例1における、製造工程を示す説明図。Explanatory drawing which shows the manufacturing process in Example 1. FIG. 実施例1における、熱間鍛造工程直後のコンロッドの形状を示す(a)平面図、(b)側面図、(c)B−B線矢視断面拡大図。The (a) top view which shows the shape of the connecting rod in Example 1 immediately after a hot forging process, (b) Side view, (c) BB arrow directional cross-sectional enlarged view. 実施例1における、バリ抜き工程の(a)コンロッドを抜き型にセットした状態を示す説明図、(b)バリを切除した直後の状態を示す説明図。(A) Explanatory drawing which shows the state which set the connecting rod to the die | dye in the burr | flash removal process in Example 1, (b) Explanatory drawing which shows the state immediately after excising a burr | flash. 実施例1における、冷間コイニング工程の(a)コンロッドを軽加工用のコイニング型にセットした状態の説明図、(b)コイニング型によってコンロッドのコラム部を挟持した状態の説明図、(c)C−C線矢視断面拡大図。(A) In the cold coining process in Example 1, (a) An explanatory diagram of a state where the connecting rod is set in a coining die for light processing, (b) An explanatory diagram of a state in which the column portion of the connecting rod is clamped by the coining die, (c) FIG. 実施例1における、冷間コイニング工程の(a)コンロッドを重加工用のコイニング型にセットした状態の説明図、(b)コイニング型によってコンロッドのコラム部を挟持した状態の説明図、(c)C−C線矢視断面拡大図。(A) In the cold coining process in Example 1, (a) An explanatory diagram of a state where the connecting rod is set in a coining die for heavy machining, (b) An explanatory diagram of a state in which the column portion of the connecting rod is clamped by the coining die, (c) FIG. 実施例2中の比較例における、バリ抜き工程の(a)コンロッドを抜き型にセットした状態を示す説明図、(b)バリを切除した直後の状態を示す説明図。In the comparative example in Example 2, (a) Explanatory drawing which shows the state which set the connecting rod to the die | dye in the burr | flash removal process, (b) Explanatory drawing which shows the state immediately after excising a burr | flash. 実施例2における、変形状態の評価方法を示す説明図。Explanatory drawing which shows the evaluation method of a deformation | transformation state in Example 2. FIG.

符号の説明Explanation of symbols

1 コンロッド
11 大端部
12 小端部
13 コラム部
131 リブ
2 バリ
4 加圧型
5 抜き型
50 抜き穴
51 バリ切断刃
6 拘束型
61 収容凹部
DESCRIPTION OF SYMBOLS 1 Connecting rod 11 Large end part 12 Small end part 13 Column part 131 Rib 2 Burr 4 Pressurization type 5 Punching die 50 Punching hole 51 Burr cutting blade 6 Restraint type 61 Housing recessed part

Claims (2)

素材に熱間鍛造を施して、大端部と小端部とこれらを繋ぐ断面略H型のコラム部とを有すると共に外周部にバリを備えたコンロッドを成形する熱間鍛造工程と、上記コンロッドの外周部に生じた上記バリを除去するバリ抜き工程と、上記大端部、上記小端部および上記コラム部に冷間コイニングを施す冷間コイニング工程とを含むコンロッドの製造方法において、
上記バリ抜き工程においては、抜き穴を有すると共にその周囲にバリ切断刃を備えた抜き型を用い、該抜き型の上記抜き穴に上記コンロッドを挿入して上記バリを上記バリ切断刃に当接させ、
上記抜き穴を貫通突出した上記コンロッドの少なくとも上記コラム部に対し、該コラム部の両側のリブが開く方向に変形することを阻止するように拘束する拘束型を当接させ、
該拘束型による上記コラム部の拘束状態を維持したまま、加圧型によって上記コンロッドを押圧して上記バリを上記バリ切断刃に押しつけることにより、上記バリの切除を行うことを特徴とするコンロッドの製造方法。
A hot forging step in which a hot forging process is performed to form a connecting rod having a large end portion, a small end portion, and a column section having a substantially H-shaped cross section connecting the large end portion and a burr on the outer peripheral portion, and the above connecting rod. In a method for manufacturing a connecting rod, including a deburring process for removing the burr generated on the outer peripheral part of the sheet, and a cold coining process for performing cold coining on the large end part, the small end part and the column part,
In the deburring step, a punching die having a punching hole and a burr cutting blade around it is used, and the connecting rod is inserted into the punching hole of the punching die so that the burr is brought into contact with the burr cutting blade. Let
A constraining die that is constrained so as to prevent the ribs on both sides of the column part from being deformed in an opening direction is brought into contact with at least the column part of the connecting rod protruding through the punched hole;
Manufacturing the connecting rod characterized in that the burr is cut off by pressing the connecting rod by a pressure die and pressing the burr against the burr cutting blade while maintaining the constrained state of the column portion by the restricting die. Method.
請求項1において、上記拘束型は、上記抜き型から突出した上記コラム部の両側の上記リブの先端部を収容する収容凹部を備えていることを特徴とするコンロッドの製造方法。   2. The method of manufacturing a connecting rod according to claim 1, wherein the constraining die includes housing recesses for housing the tip portions of the ribs on both sides of the column portion protruding from the punching die.
JP2005136159A 2005-05-09 2005-05-09 Con'rod manufacturing method Pending JP2006312978A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102463316A (en) * 2010-11-16 2012-05-23 上海交大中京锻压有限公司 Finishing die mold structure for stainless steel die forging
KR101184586B1 (en) * 2012-04-02 2012-09-21 주식회사 신일 Drawing method for forging and apparatus thereof
CN103111570A (en) * 2012-12-07 2013-05-22 无锡透平叶片有限公司 Flash trimming mechanism of blade forging pieces
CN110102631A (en) * 2019-06-03 2019-08-09 遵义航天新力精密铸锻有限公司 Superthin structure non-ferrous metal nearly shaped component edge grinding buster only

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102463316A (en) * 2010-11-16 2012-05-23 上海交大中京锻压有限公司 Finishing die mold structure for stainless steel die forging
KR101184586B1 (en) * 2012-04-02 2012-09-21 주식회사 신일 Drawing method for forging and apparatus thereof
CN103111570A (en) * 2012-12-07 2013-05-22 无锡透平叶片有限公司 Flash trimming mechanism of blade forging pieces
CN110102631A (en) * 2019-06-03 2019-08-09 遵义航天新力精密铸锻有限公司 Superthin structure non-ferrous metal nearly shaped component edge grinding buster only

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