JPH0312980B2 - - Google Patents
Info
- Publication number
- JPH0312980B2 JPH0312980B2 JP60103430A JP10343085A JPH0312980B2 JP H0312980 B2 JPH0312980 B2 JP H0312980B2 JP 60103430 A JP60103430 A JP 60103430A JP 10343085 A JP10343085 A JP 10343085A JP H0312980 B2 JPH0312980 B2 JP H0312980B2
- Authority
- JP
- Japan
- Prior art keywords
- rod
- iron
- rod portion
- conrod
- residual stress
- 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.)
- Expired - Lifetime
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 36
- 239000000463 material Substances 0.000 claims description 22
- 229910052742 iron Inorganic materials 0.000 claims description 18
- 238000003825 pressing Methods 0.000 claims description 10
- 238000005480 shot peening Methods 0.000 claims description 10
- 238000011282 treatment Methods 0.000 claims description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 9
- 229910052799 carbon Inorganic materials 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- 238000005242 forging Methods 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000002485 combustion reaction Methods 0.000 claims description 4
- 238000010411 cooking Methods 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003303 reheating Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000004049 embossing Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
Landscapes
- Forging (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
Description
Ａ 発明の目的
(1) 産業上の利用分野
本発明は内燃機関用コンロツドの製造方法に関
する。
(2) 従来の技術
従来、この種コンロツドを製造する場合、鉄系
素材に鍛造加工を施すといつた方法が知られてい
る。
この場合、コンロツドの強度を向上させる手段
としては鉄系素材の化学成分の調整、コンロツド
への各種熱処理の実施等が採用されている。この
種手段はコンロツド心部の強度を向上させるため
に有効である。
(3) 発明が解決しようとする問題点
前記コンロツドにおいて、少なくとも桿部の寸
法精度を向上させるためには、鍛造後曲がり、ね
じれ等を除去すべく、桿部形状を矯正する冷間押
圧加工を採用するのが簡便である。
しかしながら、前記冷間押圧加工を採用する
と、それに起因して桿部の表皮部に切欠感度の鋭
敏な部分が発生するため、機関運転中大きな座屈
荷重を受ける桿部において、前記部分を起点とし
た破壊が考えられる。したがつて桿部の寸法精度
を向上させると共に強度をその全体に亘つて向上
させるためには、鍛造後冷間押圧加工を採用し、
また前記強度向上手段に、表皮部における切欠感
度を低下させる手段を加える必要がある。
本発明は上記に鑑み提案されたもので、寸法精
度が良いことは勿論のこと、心部の強度向上を図
ると共に表皮層の切欠感度を低下させ、全体に亘
つて強度バランスのとれた桿部を持つコンロツド
を得ることのできる前記製造方法を提供すること
を目的とする。
Ｂ 発明の構成
(1) 課題を解決するための手段
本発明は、炭素含有量が0.1重量％以上であり、
且つロツクウエル硬さHRＣが20以上の鉄系素材
に鍛造加工を施してコンロツド形状の鍛造品を得
る工程と；前記鍛造品の少なくとも桿部に、その
形状を矯正する冷間押圧加工を施す工程と；前記
桿部にシヨツトピーニング処理を施してその桿部
の表皮部に圧縮残留応力を付与する工程と；を用
いることを特徴とする。
(2) 作用
炭素含有量が0.1重量％であり、且つロツクウ
エル硬さHRＣが20以上の鉄系素材を用いること
により、コンロツド心部の強度の向上が図られ
る。
また少なくとも桿部に冷間押圧加工を施すこと
により、その桿部の寸法精度を向上させることが
可能である。さらに冷間押圧加工を施された桿部
にシヨツトピーニング処理を施して、その表皮部
に圧縮残留応力を付与するので、表皮部の切欠感
度を低下させることができる。
これらの手段を採用することにより、寸法精度
が良く、また全体に亘つて強度バランスがとれて
おり、優れた疲労強度を有する桿部を備えたコン
ロツドを得ることができる。
(3) 実施例
第１、第２図は内燃機関用コンロツド１を示
し、桿部１ａの両端に小端部１ｂおよび大端部１
ｃがそれぞれ連設される。
表Ｉはコンロツド用鉄系素材の化学成分および
ロツクウエル硬さHRＣを示す。鉄系素材No.１〜
５は炭素含有量が0.1重量％以上に設定されてお
り、鉄系素材No.６は炭素含有量が0.1重量％未満
に設定されている。
A. Object of the Invention (1) Industrial Application Field The present invention relates to a method of manufacturing a conrod for an internal combustion engine. (2) Conventional Technology Conventionally, when manufacturing this type of connecting rod, a method is known in which iron-based materials are forged. In this case, methods for improving the strength of the stove include adjusting the chemical composition of the iron-based material and subjecting the stove to various heat treatments. This type of measure is effective for increasing the strength of the connecting rod core. (3) Problems to be Solved by the Invention In order to improve the dimensional accuracy of at least the rod portion of the above-mentioned cooking rod, cold pressing is performed to correct the shape of the rod portion in order to remove bending, twisting, etc. after forging. It is easy to adopt. However, when the above-mentioned cold pressing process is adopted, a sensitive part of the notch is generated in the skin part of the rod part. It is possible that the damage caused by Therefore, in order to improve the dimensional accuracy of the rod part and the overall strength, we adopted cold pressing after forging.
Furthermore, it is necessary to add means for reducing the notch sensitivity in the skin portion to the strength improving means. The present invention has been proposed in view of the above, and it not only has good dimensional accuracy, but also improves the strength of the core, reduces the notch sensitivity of the skin layer, and provides a rod with balanced strength throughout. It is an object of the present invention to provide the above-mentioned manufacturing method which makes it possible to obtain a cooking stove having the following properties. B. Structure of the invention (1) Means for solving the problem The present invention has a carbon content of 0.1% by weight or more,
and a step of forging an iron-based material with a Rockwell hardness of 20 or more to obtain a conrod-shaped forged product; and applying cold pressing to at least the rod portion of the forged product to correct its shape. The method is characterized by using the steps of: applying shot peening to the rod portion to apply compressive residual stress to the skin portion of the rod portion. (2) Effect By using an iron-based material with a carbon content of 0.1% by weight and a Rockwell hardness H R C of 20 or more, the strength of the connecting rod core can be improved. Further, by subjecting at least the rod portion to cold pressing, it is possible to improve the dimensional accuracy of the rod portion. Furthermore, shot peening is applied to the cold-pressed rod portion to impart compressive residual stress to the skin portion, thereby reducing the notch sensitivity of the skin portion. By employing these means, it is possible to obtain a conrod having a rod portion with good dimensional accuracy, well-balanced strength throughout, and excellent fatigue strength. (3) Embodiment Figures 1 and 2 show a connecting rod 1 for an internal combustion engine, with a small end 1b and a large end 1 at both ends of a rod 1a.
c are provided consecutively. Table I shows the chemical composition and Rockwell hardness HRC of the ferrous materials for stove rods. Iron-based materials No.1~
In No. 5, the carbon content is set to 0.1% by weight or more, and in iron-based material No. 6, the carbon content is set to less than 0.1% by weight.
【表】
表Ｉにおける鉄系素材No.１〜６を用いたコンロ
ツドの製造工程は以下の通りである。
(a) 鉄系素材No.１および２の場合
略1200℃に加熱された鉄系素材に型鍛造を施
してコンロツド形状の鍛造品を得る→鍛造品を
空冷する→鍛造品をブラストマシンに設置して
それに30分間スケール除去処理を施す→鍛造品
の桿部１ａに型押しまたはローラ処理による冷
間押圧加工を施して形状矯正を行う→鍛造品を
直径0.8mmのシヨツトを使用するシヨツトピー
ニングマシンに設置して、その冷間押圧加工を
施された桿部１ａに30分間のシヨツトピーニン
グ処理を施し、桿部１ａの表皮部に圧縮残留応
力を付与する。
(b) 鉄系素材No.３および４の場合
鉄系素材No.３は機械構造用炭素鋼に相当し、
同No.４はこの鋼におけるクロム含有量を増して
硬度の向上を図つたものである。
略1200℃に加熱された鉄系素材に型鍛造加工
を施してコンロツド形状の鍛造品を得る→鍛造
品に850℃にて、30分間再加熱処理を施す→鍛
造品に焼入れ処理を施す→鍛造品を500℃にて
60分間加熱してそれに焼戻し処理を施す→以下
スケール除去処理、冷間押圧加工およびシヨツ
トピーニング処理を前記(a)の場合と同様に行
う。
(c) 鉄系素材No.５および６の場合
鉄系素材No.５は同No.３の鋼におけるクロム含
有量を増し、またモリブデンを添加して硬度の
向上を図つたものである。同No.６は前述のよう
に炭素含有量が0.1重量％未満に設定されてい
る外は前記No.３と成分的に略同じである。
この場合には前記(b)における再加熱処理を
870℃、30分間の条件下で行い、また焼戻し処
理を200℃、60分間の条件下で行うものでその
外の各種処理は前記(b)の場合と同じである。
表は前記各工程を経て得られたコンロツド
１の桿部１ａにおける圧縮残留応力の値を示
す。コンロツドNo.１〜６は鉄系素材No.１〜６に
それぞれ対応する。[Table] The manufacturing process of stove rods using iron-based materials No. 1 to 6 in Table I is as follows. (a) In the case of iron-based materials No. 1 and 2 Die forging is performed on the iron-based material heated to approximately 1200℃ to obtain a conrod-shaped forged product → the forged product is air-cooled → the forged product is installed in a blast machine Then, the rod part 1a of the forged product is subjected to cold press processing by embossing or roller processing to correct its shape.→The forged product is subjected to shot peening using a shot with a diameter of 0.8 mm. The rod section 1a, which has been installed in a machine and subjected to cold pressing, is shot peened for 30 minutes to impart compressive residual stress to the skin of the rod section 1a. (b) In the case of iron-based materials No. 3 and 4 Iron-based material No. 3 corresponds to carbon steel for machine structures,
No. 4 is a steel with increased chromium content to improve hardness. Die forging is performed on iron-based material heated to approximately 1200℃ to obtain a conrod-shaped forged product → Reheating the forged product at 850°C for 30 minutes → Applying quenching treatment to the forged product → Forging Products at 500℃
It is heated for 60 minutes and then subjected to tempering treatment.Then, scale removal treatment, cold pressing and shot peening treatment are carried out in the same manner as in the case (a) above. (c) Cases of iron-based materials No. 5 and 6 Iron-based material No. 5 is the steel of No. 3 with increased chromium content and the addition of molybdenum to improve hardness. No. 6 has substantially the same composition as No. 3 except that the carbon content is set to less than 0.1% by weight as described above. In this case, the reheating treatment in (b) above is performed.
The process was carried out at 870°C for 30 minutes, and the tempering process was carried out at 200°C for 60 minutes; other treatments were the same as in (b) above. The table shows the values of compressive residual stress in the rod portion 1a of the connecting rod 1 obtained through each of the above steps. Conrod Nos. 1 to 6 correspond to iron-based materials Nos. 1 to 6, respectively.
【表】
第３図はコンロツドNo.１と同No.６の疲労強度試
験結果を示す。線a1はコンロツドNo.１に、また線
a2はコンロツドNo.１と同じ材質を有するが、シヨ
ツトピーニング処理を施さない場合にそれぞれ該
当し、第３図よりシヨツトピーニング処理を施す
ことにより疲労強度が20〜30％向上することが明
らかである。他のコンロツドNo.２〜５についても
同No.１と同程度の疲労強度が得られる。
一方、線b1はコンロツドNo.６に、また線b2はコ
ンロツドNo.６と同じ材質を有するがシヨツトピー
ニング処理を施さない場合にそれぞれ該当し、第
３図よりシヨツトピーニング処理を施しても施さ
なくても疲労強度が殆ど変化しないことが明らか
である。
これはコンロツドNo.６においては、その鉄系素
材の炭素含有量が0.1重量％未満に設定されてい
ることに起因しロツクウエル硬さHRＣが12と低
く、したがつて硬度が不足するためシヨツトピー
ニング処理によつて大きな圧縮残留応力を付与し
得ないからである。この問題を解消するために
は、鉄系素材の炭素含有量が0.1重量％以上であ
り、且つロツクウエル硬さHRＣが20以上である
ことが必要である。
圧縮残留応力は30〜100Kg／mm2が適当であり、
30Kg／mm2未満では十分な強度を得ることができ
ず、一方、100Kg／mm2を上回るとシヨツトの投射
時間および放射量の増大により面粗度が劣化する
ため切欠感度の鋭敏な部分が発生して逆に強度の
低下を招き、また外観品質も悪くなる。
なお、冷間押圧加工処理は小端部１ｂ、大端部
１ｃを含むコンロツド全体に施してもよく、その
場合にはコンロツド全体にシヨツトピーニング処
理を施すこともある。
Ｃ 発明の効果
本発明によれば、炭素含有量が0.1重量％以上
であり、且つロツクウエル硬さHRＣが20以上の
鉄系素材を用いて、それに鍛造加工、冷間押圧加
工およびシヨツトピーニング処理を行うことによ
り、寸法精度が良好であることは勿論のこと、全
体に亘つて強度バランスがとれており、優れた疲
労強度を有する桿部を備えたコンロツドを提供す
ることができる。[Table] Figure 3 shows the fatigue strength test results for conrods No. 1 and No. 6. Line a 1 goes to conrod No. 1, and line
A 2 has the same material as cooking stove No. 1, but it corresponds to the case where shot peening is not applied, and as shown in Figure 3, fatigue strength can be improved by 20 to 30% by applying shot peening. it is obvious. The other condensing rods No. 2 to 5 also have fatigue strengths comparable to those of No. 1. On the other hand, line b 1 corresponds to condensing rod No. 6, and line b 2 corresponds to the case where the material is the same as condensing rod No. 6 but is not subjected to shot peening treatment. It is clear that the fatigue strength hardly changes even if it is applied or not. This is due to the fact that the carbon content of the iron-based material is set to less than 0.1% by weight in stove No. 6, and the Rockwell hardness H R C is low at 12, resulting in insufficient hardness. This is because shot peening treatment cannot impart large compressive residual stress. In order to solve this problem, it is necessary that the iron-based material has a carbon content of 0.1% by weight or more and a Rockwell hardness H R C of 20 or more. The appropriate compressive residual stress is 30 to 100Kg/ mm2 ,
If it is less than 30Kg/mm2, sufficient strength cannot be obtained, while if it exceeds 100Kg/ mm2 , the surface roughness will deteriorate due to the increase in shot projection time and radiation amount, resulting in areas with acute notch sensitivity. On the contrary, the strength deteriorates and the appearance quality also deteriorates. The cold pressing process may be applied to the entire conrod including the small end 1b and the large end 1c, and in that case, the entire conrod may be subjected to shot peening. C. Effects of the Invention According to the present invention, a ferrous material having a carbon content of 0.1% by weight or more and a Rockwell hardness H R C of 20 or more is used, and is subjected to forging, cold pressing and shot processing. By performing the peening treatment, it is possible to provide a condensing rod that not only has good dimensional accuracy but also has a well-balanced strength throughout and has a rod portion that has excellent fatigue strength.
第１図はコンロツドの正面図、第２図は第１図
−線断面図、第３図はコンロツドの疲労強度
試験結果を示すグラフである。
１……コンロツド、１ａ……桿部、１ｂ……小
端部、１ｃ……大端部。
FIG. 1 is a front view of the cooking stove, FIG. 2 is a sectional view taken along the line shown in FIG. 1, and FIG. 3 is a graph showing the fatigue strength test results of the cooking stove. 1... Conn rod, 1a... Rod part, 1b... Small end part, 1c... Large end part.
Claims (1)
ツクウエル硬さHRＣが20以上の鉄系素材に鍛造
加工を施してコンロツド形状の鍛造品を得る工程
と；前記鍛造品の少なくとも桿部に、その形状を
矯正する冷間押圧加工を施す工程と；前記桿部に
シヨツトピーニング処理を施してその桿部の表皮
部に圧縮残留応力を付与する工程と；よりなる内
燃機関用コンロツドの製造方法。 ２ 前記圧縮残留応力は30〜100Kg／mm2に設定さ
れる特許請求の範囲第１項記載の内燃機関用コン
ロツドの製造方法。[Scope of Claims] 1. A step of forging an iron-based material having a carbon content of 0.1% by weight or more and a Rockwell hardness H R C of 20 or more to obtain a conrod-shaped forged product; A step of applying cold pressing to correct the shape of at least the rod portion of the product; and a step of applying a compressive residual stress to the skin portion of the rod portion by subjecting the rod portion to shot peening treatment. Method for manufacturing conrods for internal combustion engines. 2. The method for manufacturing a connecting rod for an internal combustion engine according to claim 1, wherein the compressive residual stress is set to 30 to 100 Kg/mm 2 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10343085A JPS61262440A (en) | 1985-05-15 | 1985-05-15 | Manufacture of conrod for internal-combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10343085A JPS61262440A (en) | 1985-05-15 | 1985-05-15 | Manufacture of conrod for internal-combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61262440A JPS61262440A (en) | 1986-11-20 |
| JPH0312980B2 true JPH0312980B2 (en) | 1991-02-21 |
Family
ID=14353819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10343085A Granted JPS61262440A (en) | 1985-05-15 | 1985-05-15 | Manufacture of conrod for internal-combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61262440A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2699602B2 (en) * | 1990-02-16 | 1998-01-19 | トヨタ自動車株式会社 | Manufacturing method of connecting rod |
| AU2003265271A1 (en) * | 2002-07-12 | 2004-02-02 | David C. Swenson | Connecting rod assembly |
| JP5306795B2 (en) * | 2008-12-24 | 2013-10-02 | ヤマハ発動機株式会社 | Connecting rod, internal combustion engine, transportation device, and manufacturing method of connecting rod |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5820690A (en) * | 1981-07-30 | 1983-02-07 | 三井金属エンジニアリング株式会社 | Reinforcing structure of connecting section in panel structure |
| JPS5934210A (en) * | 1982-07-28 | 1984-02-24 | ユリウス・ブルム・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング | Drawer guide assembly for drawers |
| JPS5985803A (en) * | 1982-11-08 | 1984-05-17 | Toyota Motor Corp | Production of sintered and forged connecting rod |
-
1985
- 1985-05-15 JP JP10343085A patent/JPS61262440A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5820690A (en) * | 1981-07-30 | 1983-02-07 | 三井金属エンジニアリング株式会社 | Reinforcing structure of connecting section in panel structure |
| JPS5934210A (en) * | 1982-07-28 | 1984-02-24 | ユリウス・ブルム・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング | Drawer guide assembly for drawers |
| JPS5985803A (en) * | 1982-11-08 | 1984-05-17 | Toyota Motor Corp | Production of sintered and forged connecting rod |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61262440A (en) | 1986-11-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |