JP2000230537A - Strong driving shaft having superior torsional fatigue characteristic, and manufacture thereof - Google Patents
Strong driving shaft having superior torsional fatigue characteristic, and manufacture thereofInfo
- Publication number
- JP2000230537A JP2000230537A JP11031458A JP3145899A JP2000230537A JP 2000230537 A JP2000230537 A JP 2000230537A JP 11031458 A JP11031458 A JP 11031458A JP 3145899 A JP3145899 A JP 3145899A JP 2000230537 A JP2000230537 A JP 2000230537A
- Authority
- JP
- Japan
- Prior art keywords
- drive shaft
- balance weight
- strength
- projection
- welding
- 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.)
- Granted
Links
Landscapes
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、回転の不釣り合い
を調整するバランスウェイトが取付けられた動力伝達用
駆動軸とその製造方法に関する。さらに詳述すれば、本
発明は、乗用車・トラックのようなエンジン推進車両の
エンジン推進力を各車輪に伝える駆動軸、例えばプロペ
ラシャフト、ドライブシャフトといった駆動軸とその製
造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission drive shaft to which a balance weight for adjusting rotational imbalance is attached, and a method of manufacturing the same. More specifically, the present invention relates to a drive shaft for transmitting the engine propulsion of an engine propulsion vehicle such as a car or truck to each wheel, for example, a drive shaft such as a propeller shaft or a drive shaft, and a method of manufacturing the same.
【０００２】[0002]
【従来の技術】自動車や産業機械などにおいてエンジン
からの動力伝達用に長尺の駆動軸が使用されている。こ
の駆動軸は高速回転するため、回転バランスが悪ければ
振動が発生し、騒音や故障の原因となる。このため駆動
軸では、回転時の不釣り合いを調整する必要がある。そ
の方法には種々あるが、駆動軸の一部にバランスウェイ
トをプロジェクション溶接で接合する方法が一般に多用
されている。2. Description of the Related Art A long drive shaft is used for transmitting power from an engine in automobiles and industrial machines. Since this drive shaft rotates at high speed, if the rotation balance is poor, vibration is generated, which causes noise and failure. For this reason, it is necessary to adjust imbalance during rotation of the drive shaft. Although there are various methods, a method of joining a balance weight to a part of a drive shaft by projection welding is generally widely used.
【０００３】プロジェクション溶接ではバランスウェイ
トの湾曲面の内側に１個あるいは数個のプロジェクショ
ン (突起) を設け、この突起を中空軸に押し付けながら
通電し、そのときの抵抗発熱を利用して溶接を行うもの
である。In projection welding, one or several projections (projections) are provided inside a curved surface of a balance weight, and current is applied while pressing these projections against a hollow shaft, and welding is performed by utilizing resistance heat generated at that time. Things.
【０００４】ところで、近年、環境問題などから自動車
の低燃費化が求められ、駆動軸については軽量化が求め
られている。そのため駆動軸の素材である鋼板にも高強
度・薄肉化が進められている。現在、目標とされている
のは50kgf/mm2 以上の引張強度、厚さ3.0mm 以下の薄板
から駆動軸を製造することである。また、従来の仕様の
ものであっても、駆動軸という最重要部品の信頼性の改
善のために、更なる疲労寿命の改善が求められている。[0004] In recent years, low fuel consumption of automobiles has been demanded due to environmental problems and the like, and a light weight drive shaft has been demanded. For this reason, steel sheets, which are the material of the drive shaft, are being made to have higher strength and thinner wall thickness. At present, the target is to manufacture the drive shaft from a thin plate with a tensile strength of 50 kgf / mm 2 or more and a thickness of 3.0 mm or less. Further, even with conventional specifications, further improvement in fatigue life is required to improve the reliability of the drive shaft, the most important component.
【０００５】このような高強度薄板材料で制作した駆動
軸に、従来の電気抵抗を利用したプロジェクション溶接
でバランスウェイトを取り付けると、バランスウェイト
の接合部には、駆動中のねじり荷重の繰り返しによる疲
労亀裂が発生する可能性がある。この現象は、従来の仕
様の駆動軸においても見られたが、材料が高強度化さ
れ、また薄肉化されると特に顕著になってくる。When a balance weight is attached to a drive shaft made of such a high-strength thin plate material by projection welding utilizing conventional electric resistance, the joint of the balance weight is subject to fatigue due to repeated torsional load during driving. Cracks can occur. This phenomenon was observed in the drive shaft of the conventional specification, but it becomes particularly remarkable when the material is strengthened and thinned.
【０００６】このような疲労強度の低下に対する改善策
は従来にあってもいくつか提案されている。例えば、特
開平７−317844号公報では、バランスウェイトの接合部
におけるプロジェクションの径Ｄに対する接合部の径ｄ
の比(d/D) が0.6 〜1.0 となるような溶接を行って接合
部の応力集中を緩和し、さらに材料を低炭素鋼化するこ
とにより溶接による熱影響部の硬化度を小さくすること
で疲労に対する切り欠き感受性を小さくし、疲労強度を
向上させる方法が提案されている。[0006] Some measures for improving the fatigue strength have been proposed. For example, in Japanese Patent Application Laid-Open No. Hei 7-317844, the diameter d of the joint with respect to the diameter D of the projection at the joint of the balance weight is disclosed.
To reduce the stress concentration at the joint by performing welding so that the ratio (d / D) becomes 0.6 to 1.0, and to reduce the degree of hardening of the heat-affected zone by welding by reducing the material to low carbon steel. A method for reducing notch sensitivity to fatigue and improving fatigue strength has been proposed.
【０００７】また、特開平９−291974号公報ではバラン
スウェイトのプロジェクション (突起) の直径を1.5 〜
4.0 mmとすることにより接合部の幾何学形状を改善して
疲労寿命を向上させる方法が提案されている。In Japanese Patent Application Laid-Open No. 9-291974, the diameter of the projection (projection) of the balance weight is set to 1.5 to
There has been proposed a method for improving the fatigue life by improving the geometrical shape of the joint by setting it to 4.0 mm.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、特開平
７−317844号公報の開示する方法は、バランスウェイト
の接合部に対する応力集中を緩和することでバランスウ
ェイトの溶接部の疲労寿命向上に効果はあるものの、更
なる疲労寿命の改善が求められ、特に引張強さが50kgf/
mm2 以上で、厚さ2.0mm 以下というような薄肉高強度鋼
管の場合には決定的な方法とは言えない。However, the method disclosed in Japanese Patent Application Laid-Open No. Hei 7-317844 is effective in improving the fatigue life of the welded portion of the balance weight by relaxing the concentration of stress on the joint of the balance weight. However, further improvement in fatigue life is required, especially when the tensile strength is 50 kgf /
In the case of a thin high-strength steel pipe having a thickness of not less than 2 mm and a thickness of not more than 2.0 mm, this method cannot be said to be a definitive method.
【０００９】一方、特開平９−291974号公報の開示する
方法では、応力集中が生じることには変わりなく、溶接
時の急熱急冷による金属組織の変化による影響が解決さ
れていないので、大きな疲労寿命の改善は望めない。On the other hand, in the method disclosed in Japanese Patent Application Laid-Open No. 9-291974, stress concentration still occurs, and the influence of the change in the metal structure due to rapid heating and quenching during welding is not solved. Lifetime improvement cannot be expected.
【００１０】本発明の目的は、疲労寿命をさらに改善し
て信頼性をさらに高めた駆動軸、特に引張強さが50kgf/
mm2 以上の高強度材料の薄肉の鋼管で製作された駆動軸
であっても疲労寿命の長い駆動軸、およびこのような駆
動軸を製造する方法を提供することにある。[0010] It is an object of the present invention to provide a drive shaft having a further improved fatigue life and further improved reliability, in particular, a tensile strength of 50 kgf / kg.
An object of the present invention is to provide a drive shaft having a long fatigue life even with a drive shaft made of a thin steel pipe made of a high-strength material of mm 2 or more, and a method of manufacturing such a drive shaft.
【００１１】[0011]
【課題を解決するための手段】従来の知見では、バラン
スウェイトを接合した引張強さが50kgf/mm2 以上の高強
度材料で製造した駆動軸をねじり疲労試験にかけた場合
に、バランスウェイト接合部が優先的に破損する。そこ
で、駆動軸のねじり疲労寿命の向上のためには、バラン
スウェイト接合部の疲労寿命のさらなる向上が必要とな
る。Means for Solving the Problems According to the conventional knowledge, when a drive shaft made of a high-strength material having a tensile strength of 50 kgf / mm 2 or more to which a balance weight is joined is subjected to a torsional fatigue test, a balance weight joint is formed. Is preferentially damaged. In order to improve the torsional fatigue life of the drive shaft, it is necessary to further improve the fatigue life of the balance weight joint.
【００１２】ところで、前述の特開平７−317844号公報
に記載の方法において必ずしも疲労寿命が十分でない原
因を検討した結果、次のような知見を得た。すなわち、
上記公報では、バランスウェイトをプロジェクション溶
接で鋼管に接合する場合、接合部のコーナの位置がプロ
ジェクション溶接による熱影響部の端部にほぼ一致して
いる。そのため、応力集中が生じる部分と熱影響による
硬度急変部が一致しているので破損し易い状態となるの
である。By the way, as a result of studying the cause of insufficient fatigue life in the method described in the above-mentioned Japanese Patent Application Laid-Open No. 7-317844, the following findings were obtained. That is,
In the above-mentioned publication, when the balance weight is joined to the steel pipe by projection welding, the position of the corner of the joint almost coincides with the end of the heat-affected zone by projection welding. Therefore, the portion where the stress concentration occurs and the portion where the hardness suddenly changes due to the thermal effect coincide with each other, so that the portion is easily broken.
【００１３】そこで、種々検討の結果、疲労寿命を改善
するには、バランスウェイトの接合部のコーナの位置と
プロジェクション溶接による熱影響部の端部との重なり
を防止すること、例えば接合部のコーナを熱影響部の端
部から内側に0.5 mm以上の位置にくるようにすればよい
ことが判明した。Therefore, as a result of various studies, to improve the fatigue life, it is necessary to prevent the position of the corner of the joint of the balance weight from overlapping with the end of the heat-affected zone by projection welding. It has been found that it is sufficient to set the distance from the end of the heat-affected zone 0.5 mm or more.
【００１４】このように接合部のコーナの応力集中が生
じる部分と、硬度が急変することによる疲労に対する切
り欠き感受性の大きい部分とが相対的に離れた位置にく
ることになり、したがって、バランスウェイトの接合部
全体としての疲労寿命は向上することになる。As described above, the part where the stress concentration at the corner of the joint is generated and the part where the notch susceptibility to fatigue due to the rapid change in hardness is relatively far away from each other. The fatigue life of the joint as a whole is improved.
【００１５】ここに、本発明の要旨とするところは次の
通りである。 (1) 駆動軸を構成する中空軸の一部にバランスウェイト
がプロジェクション溶接によって接合されている動力伝
達用駆動軸であって、前記中空軸は、引張強さが50kgf/
mm2 以上の鋼板から構成される鋼管であり、この鋼管と
バランスウェイトとの接合部のコーナの位置がプロジェ
クション溶接による熱影響部の端部から0.5 mm以上離れ
た位置にあることを特徴とするねじり疲労特性に優れた
高強度駆動軸。Here, the gist of the present invention is as follows. (1) A drive shaft for power transmission in which a balance weight is joined to a part of the hollow shaft constituting the drive shaft by projection welding, wherein the hollow shaft has a tensile strength of 50 kgf /
It is a steel pipe composed of a steel plate of 2 mm or more, characterized in that the position of the corner of the junction between this steel pipe and the balance weight is at least 0.5 mm away from the end of the heat-affected zone by projection welding High strength drive shaft with excellent torsional fatigue characteristics.
【００１６】(2) 前記鋼板の炭素含有量が0.05〜0.12重
量％である上記(1) 記載の高強度駆動軸。 (3) 前記接合部の最大ビッカース硬さと前記鋼管のビッ
カース硬さとの差 (δHv) が150 以下である上記(1) ま
たは(2) 記載の高強度駆動軸。 (4) 前記バランスウェイトが、引張強さが50kgf/mm2 以
上の鉄鋼材料から成る上記(1) ないし(3) のいずれかに
記載の高強度駆動軸。(2) The high-strength drive shaft according to (1), wherein the carbon content of the steel sheet is 0.05 to 0.12% by weight. (3) The high-strength drive shaft according to (1) or (2), wherein a difference (ΔHv) between the maximum Vickers hardness of the joint and the Vickers hardness of the steel pipe is 150 or less. (4) The high-strength drive shaft according to any one of (1) to (3), wherein the balance weight is made of a steel material having a tensile strength of 50 kgf / mm 2 or more.
【００１７】(5) 駆動軸を構成する中空軸の一部にバラ
ンスウェイトをプロジェクション溶接によって接合する
ことから成り、バランスウェイトの溶接する面に設けた
プロジェクションを、その１個当たりの圧力を100 〜50
0kgfとして前記中空軸に押圧し、プロジェクション１個
当たりの電流を７〜30ｋA として100 〜300ms の時間で
前記プロジェクション溶接を行うことを特徴とする、上
記(1) ないし(4) のいずれかに記載の高強度駆動軸の製
造方法。 (6) 前記プロジェクション溶接が、直流電流による電気
抵抗溶接である上記(5)に記載の高強度駆動軸の製造方
法。(5) The balance weight is joined to a part of the hollow shaft constituting the drive shaft by projection welding, and the projection provided on the welding surface of the balance weight has a pressure per unit of 100 to 100. 50
The method according to any one of (1) to (4), wherein the projection welding is performed at a time of 100 to 300 ms with a current per projection of 7 to 30 kA by pressing the hollow shaft at 0 kgf. Manufacturing method of high-strength drive shaft. (6) The method of manufacturing a high-strength drive shaft according to the above (5), wherein the projection welding is an electric resistance welding using a direct current.
【００１８】[0018]
【発明の実施の形態】図１は、本発明におけるバランス
ウェイトの駆動軸への接合の様子を説明する模式図であ
る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view for explaining the manner in which a balance weight is joined to a drive shaft according to the present invention.
【００１９】図中、その一部を断面で示す駆動軸10の表
面には予めプロジェクション11が設けられたバランスウ
ェイト12がプロジェクション溶接によって接合されてお
り、バランスウェイト12と駆動軸10との接合部14のコー
ナ16は、プロジェクション溶接によって駆動軸側に形成
された熱影響部20の端部22より0.5 mm以上内側にきてお
り、両者が重なることはない。In the figure, a balance weight 12 provided with a projection 11 in advance is joined by projection welding to the surface of a drive shaft 10, a part of which is shown in a cross section, and a joint between the balance weight 12 and the drive shaft 10 is provided. The fourteen corners 16 are 0.5 mm or more inward from the end 22 of the heat-affected zone 20 formed on the drive shaft side by projection welding, and they do not overlap.
【００２０】プロジェクション溶接によるバランスウェ
イトの駆動軸への接合はすでに公知であって、本発明に
あっても、上述の形態での接合が実現される限り、その
ような公知の手段、条件によって行えばよく、それによ
って本発明が制限されることはない。例えば、バランス
ウェイト12に設けられるプロジェクション11は１もしく
は複数であてもよく、その形状も、その断面が図示例の
ように半円球硬形であっても、あるいは円錐台形、円柱
形であってもよい。The connection of the balance weight to the drive shaft by projection welding is already known, and even in the present invention, as long as the connection in the above-described form is realized, the connection is performed by such known means and conditions. It should be noted that the present invention is not limited thereby. For example, the projection 11 provided on the balance weight 12 may be one or more, and the shape thereof may be a semi-spherical hard shape as shown in the illustrated example, or may be a truncated conical shape or a cylindrical shape. Is also good.
【００２１】本発明によれば、溶接時に溶接熱の影響を
受けて硬化する領域、つまり熱影響部は母材部分より高
硬度となり、硬度変化は中心部から周囲に向かって硬度
の低減がみられ、そのとき母材と等しい硬度となる境界
面を熱影響部の端部という。According to the present invention, the region hardened by the influence of welding heat during welding, that is, the heat-affected zone has a higher hardness than the base metal portion, and the hardness changes from the center toward the periphery. The boundary surface having the same hardness as that of the base material at that time is called an end of the heat-affected zone.
【００２２】図２はこの熱影響部20における円周方向へ
の板厚部における硬度変化を示すグラフである。図中、
３種類の鋼管 (○印、□印、△印) について、熱影響の
受けていない母材側から溶接部に向けて順次硬度測定し
た結果を示し、硬度の急変がみられる領域を熱影響部の
端部と称する。FIG. 2 is a graph showing a change in hardness of the heat-affected zone 20 at a plate thickness portion in the circumferential direction. In the figure,
For three types of steel pipes (○ mark, □ mark, △ mark), the results of the hardness measurement are shown sequentially from the unaffected base metal side to the welded part, and the area where the hardness changes rapidly is shown in the heat affected zone. Of the end.
【００２３】ここで、本発明において上述のような各限
定を行う理由を説明する。まず、鋼管とバランスウェイ
トとの接合部のコーナの位置がプロジェクション溶接に
よる熱影響部の端部から0.5 mm以上離れた位置にあると
した理由は、熱影響部からの距離が0.5 mm未満では応力
集中部と硬度の変化の大きい部分が干渉し合うので疲労
寿命向上の効果がなくなるからである。好ましくはその
距離は、1.0mm 以上である。Here, the reason for performing each of the above-mentioned limitations in the present invention will be described. First, the reason that the corner position of the joint between the steel pipe and the balance weight is located at least 0.5 mm from the end of the heat-affected zone by projection welding is that stress is reduced when the distance from the heat-affected zone is less than 0.5 mm. This is because the concentrated portion and the portion having a large change in hardness interfere with each other, so that the effect of improving the fatigue life is lost. Preferably, the distance is at least 1.0 mm.
【００２４】このような形態の溶接を実現するには、例
えば、溶接入熱量を大きくした長時間の溶接を行うこと
で実現できる。ただし、必要以上に溶接入熱を上げると
鋼管には溶融・凝固に伴い体積収縮が生じることによる
引張残留応力が広範囲にわたり生じるため、疲労強度が
低下する原因となるため、注意が必要である。Such a form of welding can be realized, for example, by performing welding for a long time with a large heat input. However, care should be taken when increasing the welding heat input more than necessary, since tensile residual stress due to volume shrinkage due to melting and solidification occurs in the steel pipe over a wide range, which causes a reduction in fatigue strength.
【００２５】また、鋼管の材料をＣ含有量が0.05〜0.12
重量％の低炭素高強度鋼管とすることによりさらに疲労
寿命の向上を図ることができるが、それは、低炭素鋼化
することにより、接合部のプロジェクション溶接による
熱影響部の硬化度δHv (鋼管の母材部と熱影響部との硬
度の差) が通常はHv200 を越えるところを200 以下とす
ることができるからである。この効果は硬化度（δHv）
をHv150 以下とすることでさらに顕著になる。Further, the material of the steel pipe has a C content of 0.05 to 0.12.
The fatigue life can be further improved by using low-carbon high-strength steel pipes of weight percent, but by using low-carbon steel, the degree of hardening of the heat-affected zone due to projection welding of the joints δHv ( This is because the difference (hardness difference between the base metal portion and the heat-affected zone) usually exceeding Hv200 can be set to 200 or less. This effect is the degree of cure (δHv)
Is set to Hv150 or less.
【００２６】さらに、バランスウェイトの材料を引張強
さが50kgf/mm2 以上、さらには、70kgf/mm2 以上の高強
度鉄鋼材料とすることにより、プロジェクション溶接に
よりバランスウェイト側に生じた引張残留応力値が増加
し、その分だけ鋼管側の残留応力値が低下するので、疲
労寿命は向上する。Further, the balance weight material is made of a high-strength steel material having a tensile strength of 50 kgf / mm 2 or more, and more preferably 70 kgf / mm 2 or more, so that the tensile residual stress generated on the balance weight side by projection welding. Since the value increases and the residual stress value on the steel pipe side decreases accordingly, the fatigue life is improved.
【００２７】本発明にかかる高強度駆動軸の製造に際し
ては、バランスウェイトの溶接面に設けたプロジェクシ
ョンを、その１個当たりの加圧力を100 〜500kgfとして
中空軸に押圧し、上記プロジェクション１個当たりの電
流を７〜30kAとして100 〜300ms の時間で溶接を行う。
好適加圧力は 150〜350kgf、好適電流は８〜15kAであ
る。In manufacturing the high-strength drive shaft according to the present invention, the projection provided on the welding surface of the balance weight is pressed against the hollow shaft at a pressure of 100 to 500 kgf per unit, and the projection is applied to each of the projections. Welding is performed for 100 to 300 ms with the current of 7 to 30 kA.
The preferred pressure is 150-350 kgf and the preferred current is 8-15 kA.
【００２８】この方法により、バランスウェイトの接合
部のコーナの位置がプロジェクション溶接による熱影響
部の端部から0.5 mm以上の位置にあるように接合するこ
とができる。According to this method, the joining can be performed such that the corner position of the joining portion of the balance weight is at least 0.5 mm from the end of the heat affected zone by the projection welding.
【００２９】本発明の場合、プロジェクションの大き
さ、つまり直径は問題にならず、いずれの大きさのプロ
ジェクションであっても、上述のように溶接条件を変更
することで、接合部のコーナを溶接熱影響部の端部から
0.5mm 以上離れたものとすることができる。上記溶接電
源には、交流、直流のいずれを使用してもよいが、接合
部形状安定のため直流電流を用いるのが望ましい。In the case of the present invention, the size of the projection, that is, the diameter does not matter. Regardless of the size of the projection, by changing the welding conditions as described above, the corner of the joint can be welded. From the end of the heat-affected zone
It can be more than 0.5mm apart. As the welding power source, either AC or DC may be used, but it is preferable to use DC current for stabilizing the shape of the joint.
【００３０】このように本発明の駆動軸の特徴は、鋼管
とバランスウェイトとの接合部において、接合部のコー
ナと熱影響部の端部との距離が0.5 mm以上であり、そし
て鋼管として高強度鋼管を用いることであり、その好適
態様によれば、低炭素鋼高強度鋼鋼管を用いることであ
り、さらに好ましくは熱影響部の最大ビッカース硬度と
母材である鋼管のビッカース硬度との差、すなわち硬化
度がHv150 以下であること、あるいはバランスウェイト
の材質を50kgf/mm2 以上の引張強さを有する鉄鋼材料と
することである。As described above, the feature of the drive shaft of the present invention is that at the joint between the steel pipe and the balance weight, the distance between the corner of the joint and the end of the heat-affected zone is 0.5 mm or more, and the height of the steel pipe is high. The preferred embodiment is to use a low-carbon steel high-strength steel pipe, more preferably the difference between the maximum Vickers hardness of the heat-affected zone and the Vickers hardness of the steel pipe as the base material. That is, the degree of hardening is Hv 150 or less, or the material of the balance weight is a steel material having a tensile strength of 50 kgf / mm 2 or more.
【００３１】図３は、従来の駆動軸の例を示すもので、
駆動軸10の表面にはバランスウェイト12がプロジェクシ
ョン溶接によって両者の接合部を介して接合され、その
周囲には熱影響部が形成されている。FIG. 3 shows an example of a conventional drive shaft.
A balance weight 12 is joined to the surface of the drive shaft 10 by projection welding via a joint between the two, and a heat affected zone is formed around the balance weight 12.
【００３２】図示のように、従来の接合部の形状では、
応力集中するコーナの位置と溶接時の熱影響による駆動
軸の硬度急変部、つまり熱影響部の端部の位置が一致す
るので、繰り返し荷重を受けた場合に薄肉の材料では疲
労亀裂が発生し易くなる。一方、本発明によれば接合部
のコーナの位置が熱影響部の内側にあり、硬度急変部の
位置から離れているため、応力集中が生じてもコーナか
らは割れにくい。さらに材料を低炭素鋼としたことによ
り母材部と熱影響部に見られる硬化部との硬度差が小さ
いので硬度急変部においても割れにくくなる。As shown in the figure, in the conventional joint shape,
Since the position of the corner where stress concentrates and the sudden change in hardness of the drive shaft due to the heat effect during welding, that is, the position of the end of the heat-affected zone, coincide, fatigue cracks occur in thin-walled materials when repeatedly loaded. It will be easier. On the other hand, according to the present invention, since the position of the corner of the joint is inside the heat-affected zone and is far from the position of the sudden change in hardness, even if stress concentration occurs, the corner is hardly cracked from the corner. Furthermore, since the material is made of low-carbon steel, the hardness difference between the base material and the hardened portion found in the heat-affected zone is small, so that it is difficult to crack even in the rapidly changing hardness.
【００３３】かくして、本発明によれば、疲労寿命は従
来例の駆動軸と比較して、ほぼ100％増加することにな
り、駆動軸としての信頼性はさらに改善され、また駆動
軸を構成する鋼管の板厚をほぼ 1.6〜1.8 mmとしても従
来と同等の疲労寿命が得られるなど、実用上の利益は大
きい。Thus, according to the present invention, the fatigue life is increased by almost 100% as compared with the conventional drive shaft, the reliability as the drive shaft is further improved, and the drive shaft is constituted. Even if the thickness of the steel pipe is set to approximately 1.6 to 1.8 mm, the practical benefit is large, such as the same fatigue life as before can be obtained.
【００３４】[0034]
【実施例】実施例１ 表１に示す成分組成を有する鋼を溶製し、鋼片に鋳造し
たのち熱間圧延して板厚1.6 mmの熱延鋼板を製造し、こ
れを使って外径60.5mmの電縫鋼管を作成した。得られた
電縫鋼管を長さ450 mmに切断し、両端にヨークを摩擦圧
接にて取り付けた。さらに、鋼板を加工して作成したバ
ランスウェイトをプロジェクション溶接にて取り付けて
試験片とした。Example 1 A steel having the composition shown in Table 1 was melted, cast into a billet, and then hot-rolled to produce a hot-rolled steel sheet having a thickness of 1.6 mm. A 60.5 mm ERW pipe was made. The obtained electric resistance welded steel pipe was cut into a length of 450 mm, and yokes were attached to both ends by friction welding. Further, a balance weight created by processing a steel plate was attached by projection welding to obtain a test piece.
【００３５】作成した試験片を用いて、トルク振幅1.80
kN・m の繰り返しねじり荷重を負荷する疲労試験を行
い、ねじり疲労寿命を調査した。結果を表２にまとめて
示す。Using the prepared test piece, a torque amplitude of 1.80 was used.
A fatigue test in which a torsional load of kN · m was applied was performed, and the torsional fatigue life was investigated. The results are summarized in Table 2.
【００３６】表２の結果からも分かるように、本発明例
のバランスウェイトの接合部のコーナと熱影響部の端部
との距離が0.5 mm以上あるものは、疲労寿命が長く、バ
ランスウェイト溶接部から破損することもなかった。ま
た、炭素量が0.12％以下の鋼管Ａ、Ｂは、同じく炭素量
が0.12％を越える鋼管Ｃ、Ｄの場合よりも疲労寿命は長
くなる。鋼管の熱影響部の硬度化δHvもHv150 以下とな
る場合の方が長寿命となることが分かる。As can be seen from the results shown in Table 2, when the distance between the corner of the joint of the balance weight of the present invention and the end of the heat-affected zone is 0.5 mm or more, the fatigue life is longer and the balance weight welding is performed. There was no damage from the part. The steel pipes A and B having a carbon content of 0.12% or less have a longer fatigue life than the steel pipes C and D having a carbon content of more than 0.12%. It can be seen that the life is longer when the hardness δHv of the heat-affected zone of the steel pipe is also Hv150 or less.
【００３７】実施例２ 鋼管Ａ、ＢにおいてバランスウェイトをTS80キロ級とし
た場合についても実施例１を繰り返し同様に疲労試験を
行った。結果は表３にまとめて示す。表３からも分かる
ように、バランスウェイトの引張強度を50kgf/mm2 以上
とすることによってさらに疲労寿命は向上する。Example 2 In the case where the balance weight of the steel pipes A and B was set to the TS80 kg class, the fatigue test was repeated in the same manner as in Example 1. The results are summarized in Table 3. As can be seen from Table 3, the fatigue life is further improved by setting the tensile strength of the balance weight to 50 kgf / mm 2 or more.
【００３８】実施例３ 鋼管Ａ、Ｂを用い、溶接条件を種々変更してバランスウ
ェイトを溶接し、得られた試験片について実施例１と同
様に疲労試験を行った。結果は表４にまとめて示すが、
これからも分かるように、バランスウェイトを規定外の
溶接条件で取り付けると疲労寿命も短くなる。Example 3 Using steel pipes A and B, welding conditions were variously changed and balance weights were welded. The obtained test pieces were subjected to a fatigue test in the same manner as in Example 1. The results are summarized in Table 4,
As can be seen from the above, when the balance weight is attached under non-specified welding conditions, the fatigue life is shortened.
【００３９】[0039]
【表１】 [Table 1]
【００４０】[0040]
【表２】 [Table 2]
【００４１】[0041]
【表３】 [Table 3]
【００４２】[0042]
【表４】 [Table 4]
【００４３】[0043]
【発明の効果】以上説明してきたように、本発明によれ
ば、引張強度50kgf/mm2 以上の高強度材料からの高強度
駆動軸の疲労強度の改善効果が特に顕著であって、特に
近年の低燃費自動車用としての実用上の利益は大きく、
本発明の斯界における貢献は大である。As described above, according to the present invention, the effect of improving the fatigue strength of a high-strength drive shaft made of a high-strength material having a tensile strength of 50 kgf / mm 2 or more is particularly remarkable, and particularly in recent years. Practical benefits for fuel-efficient vehicles are
The contribution of the present invention in the art is significant.
【図１】本発明におけるバランスウェイトの駆動軸への
接合の様子を説明する模式図である。FIG. 1 is a schematic diagram illustrating a state of joining a balance weight to a drive shaft in the present invention.
【図２】熱影響部における硬度変化を示すグラフであ
る。FIG. 2 is a graph showing a change in hardness in a heat-affected zone.
【図３】従来例によるバランスウェイトを接合した駆動
軸の疲労亀裂の発生の様子を説明する模式図である。FIG. 3 is a schematic diagram illustrating the appearance of the generation of fatigue cracks in a drive shaft to which a balance weight is joined according to a conventional example.
Claims (6)
スウェイトがプロジェクション溶接によって接合されて
いる動力伝達用駆動軸であって、前記中空軸は、引張強
さが50kgf/mm2 以上の鋼板から構成される鋼管であり、
この鋼管とバランスウェイトとの接合部のコーナの位置
がプロジェクション溶接による熱影響部の端部から0.5
mm以上離れた位置にあることを特徴とするねじり疲労特
性に優れた高強度駆動軸。1. A power transmission drive shaft in which a balance weight is joined to a part of a hollow shaft constituting a drive shaft by projection welding, wherein the hollow shaft has a tensile strength of 50 kgf / mm 2 or more. A steel pipe made of steel sheet,
The position of the corner at the joint between this steel pipe and the balance weight is 0.5 mm from the end of the heat-affected zone by projection welding.
High-strength drive shaft with excellent torsional fatigue characteristics characterized by being located at a distance of at least mm.
％である請求項１記載の高強度駆動軸。2. The high-strength drive shaft according to claim 1, wherein the carbon content of the steel sheet is 0.05 to 0.12% by weight.
鋼管のビッカース硬さとの差 (δHv) が150 以下である
請求項１または２記載の高強度駆動軸。3. The high-strength drive shaft according to claim 1, wherein a difference (δHv) between a maximum Vickers hardness of the joining portion and a Vickers hardness of the steel pipe is 150 or less.
kgf/mm2 以上の鉄鋼材料から成る請求項１ないし３のい
ずれかに記載の高強度駆動軸。4. The balance weight has a tensile strength of 50.
4. The high-strength drive shaft according to claim 1, wherein the high-strength drive shaft is made of a steel material of kgf / mm 2 or more.
スウェイトをプロジェクション溶接によって接合するこ
とから成り、バランスウェイトの溶接する面に設けたプ
ロジェクションを、その１個当たりの圧力を100 〜500k
gfとして前記中空軸に押圧し、プロジェクション１個当
たりの電流を７〜30ｋA として100 〜300ms の時間で前
記プロジェクション溶接を行うことを特徴とする、請求
項１ないし４のいずれかに記載の高強度駆動軸の製造方
法。5. A balance weight is joined to a part of a hollow shaft constituting a drive shaft by projection welding. A projection provided on a surface of the balance weight to be welded has a pressure of 100 to 500 k per unit.
The high strength according to any one of claims 1 to 4, wherein the projection welding is performed at a time of 100 to 300 ms with the current per projection being 7 to 30 kA by pressing the hollow shaft as gf. Drive shaft manufacturing method.
による電気抵抗溶接である請求項５に記載の高強度駆動
軸の製造方法。6. The method according to claim 5, wherein the projection welding is an electric resistance welding using a direct current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03145899A JP3697922B2 (en) | 1999-02-09 | 1999-02-09 | High-strength drive shaft with excellent torsional fatigue characteristics and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03145899A JP3697922B2 (en) | 1999-02-09 | 1999-02-09 | High-strength drive shaft with excellent torsional fatigue characteristics and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000230537A true JP2000230537A (en) | 2000-08-22 |
| JP3697922B2 JP3697922B2 (en) | 2005-09-21 |
Family
ID=12331828
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03145899A Expired - Lifetime JP3697922B2 (en) | 1999-02-09 | 1999-02-09 | High-strength drive shaft with excellent torsional fatigue characteristics and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3697922B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103032446A (en) * | 2012-12-04 | 2013-04-10 | 江苏航天动力机电有限公司 | Anti-fracture structure of rib-welded shaft motor |
| WO2019098292A1 (en) * | 2017-11-15 | 2019-05-23 | 日本発條株式会社 | Joint and automotive seat frame |
| CN113891773A (en) * | 2019-05-28 | 2022-01-04 | 杰富意钢铁株式会社 | Resistance spot-welded part, resistance spot-welding method, resistance spot-welded joint, and method for manufacturing resistance spot-welded joint |
-
1999
- 1999-02-09 JP JP03145899A patent/JP3697922B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103032446A (en) * | 2012-12-04 | 2013-04-10 | 江苏航天动力机电有限公司 | Anti-fracture structure of rib-welded shaft motor |
| WO2019098292A1 (en) * | 2017-11-15 | 2019-05-23 | 日本発條株式会社 | Joint and automotive seat frame |
| JP2019089541A (en) * | 2017-11-15 | 2019-06-13 | 日本発條株式会社 | Joint body and automobile seat frame |
| US11498466B2 (en) | 2017-11-15 | 2022-11-15 | Nhk Spring Co., Ltd. | Joined body and automobile seat frame |
| CN113891773A (en) * | 2019-05-28 | 2022-01-04 | 杰富意钢铁株式会社 | Resistance spot-welded part, resistance spot-welding method, resistance spot-welded joint, and method for manufacturing resistance spot-welded joint |
| CN113891773B (en) * | 2019-05-28 | 2022-11-08 | 杰富意钢铁株式会社 | Resistance spot-welded part, resistance spot-welding method, resistance spot-welded joint, and method for manufacturing resistance spot-welded joint |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3697922B2 (en) | 2005-09-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6656079B2 (en) | Differential gear and method of making same | |
| US6855061B2 (en) | Vehicular driveshaft assembly | |
| US10661532B2 (en) | Chassis component having high durability | |
| JP2008546584A (en) | Automotive steering knuckle | |
| JP3445579B2 (en) | Bonding structure between dissimilar metal hollow members and bonding method thereof | |
| JP2000230537A (en) | Strong driving shaft having superior torsional fatigue characteristic, and manufacture thereof | |
| US5633093A (en) | Counterweight attachment technique | |
| JP2004138209A (en) | Pulley for continuously variable transmission | |
| JP3187274B2 (en) | High strength drive shaft for power transmission and method of manufacturing the same | |
| JP2002336975A (en) | Method for friction-welding pipe members made of dissimilar materials | |
| US20030057052A1 (en) | Clutch shaft stress relief | |
| US20210206198A1 (en) | Wheel for a commercial vehicle, and use thereof | |
| JP2008151153A (en) | Propeller shaft structure | |
| JP4133220B2 (en) | Manufacturing method of high-strength propeller shaft with excellent durability | |
| JP2005214335A (en) | Balance weight of propeller shaft | |
| JP2005271015A (en) | Friction welding method of steel tube and aluminum alloy hollow member | |
| JPH04187388A (en) | Friction welding method for different kinds of metallic pipes | |
| JP2005271016A (en) | Friction welding method of steel tube and aluminum alloy hollow member | |
| JP2001287040A (en) | Joined structure body and method of evaluation of joined strength of the same | |
| JPH06109085A (en) | Joint of ring gear | |
| JPH09291975A (en) | Drive shaft having excellent fatigue characteristic | |
| JPH09291973A (en) | Drive shaft having excellent fatigue characteristic | |
| JPH04126049U (en) | Propeller shaft balance weight structure | |
| JPH09291974A (en) | High performance automobile drive shaft excellent in torsional fatigue characteristic | |
| JPH10184804A (en) | Driving shaft having excellent torsional fatigue characteristics |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20041207 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050114 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20050614 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20050627 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110715 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110715 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120715 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130715 Year of fee payment: 8 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |