JPH05223663A - Production of torque detection shaft - Google Patents
Production of torque detection shaftInfo
- Publication number
- JPH05223663A JPH05223663A JP5698292A JP5698292A JPH05223663A JP H05223663 A JPH05223663 A JP H05223663A JP 5698292 A JP5698292 A JP 5698292A JP 5698292 A JP5698292 A JP 5698292A JP H05223663 A JPH05223663 A JP H05223663A
- Authority
- JP
- Japan
- Prior art keywords
- shaft
- treatment
- shaft material
- carburizing
- carbon
- 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
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、磁性材料からなる軸の
表面応力を磁気的に検出してトルクを求めるトルクセン
サのトルク検出軸の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a torque detecting shaft of a torque sensor for magnetically detecting the surface stress of a shaft made of a magnetic material to obtain a torque.
【０００２】[0002]
【従来の技術】軸表面の磁歪現象を利用してトルクを検
出できることが知られており、特許第１６９３２６号に
記載されているように、強磁性体よりなる軸材の表面に
溝を形成し、軸に作用するトルクによって生じた応力に
よる軸表面の磁気特性の変化を、軸材の近傍に配置した
コイルを用いて検出し、検出した磁気特性の変化からト
ルクを求めることが行われている。このような軸材の磁
気特性の変化を利用してトルクを検出するトルクセンサ
においては、トルク検出軸に大きな力が作用するところ
から、軸材として高強度であって降伏応力の高いものが
望まれており、通常浸炭鋼、焼入れ鋼が多く用いられて
いる。2. Description of the Related Art It is known that torque can be detected by utilizing the magnetostriction phenomenon on the surface of a shaft. As described in Japanese Patent No. 169326, a groove is formed on the surface of a shaft material made of a ferromagnetic material. , The change in the magnetic characteristics of the shaft surface due to the stress generated by the torque acting on the shaft is detected using a coil arranged near the shaft material, and the torque is obtained from the detected change in the magnetic characteristics. .. In a torque sensor that detects torque by utilizing such changes in the magnetic properties of the shaft material, a strong strength and high yield stress is desired as the shaft material because a large force acts on the torque detection shaft. In general, carburized steel and hardened steel are often used.
【０００３】また、トルク検出軸は、作用するトルクに
よる応力に対する磁気特性の変化が大きく、かつ磁気特
性の変化が直線的でヒステリシスの小さいことが望まし
い。この応力に対する磁気特性の変化は、軸の表面残留
応力に大きな影響を受け、表面残留応力を均一にする必
要がある。このため、一般に、トルクセンサ用の軸材
は、浸炭処理をした後、焼もどしやサブゼロ処理を始め
とする焼入れなどの熱処理や、ショットピーニングを始
めとする機械的な応力負荷により、表面残留応力を均一
化して磁気特性の向上を図っている。また、特開昭６０
−２５４６７８号公報に示されているように、軸材に表
面圧縮応力を作り、疲労強度、磁気特性を向上させるよ
うにしている。Further, it is desirable that the torque detecting shaft has a large change in the magnetic characteristics with respect to the stress due to the acting torque, the change in the magnetic characteristics is linear, and the hysteresis is small. The change in the magnetic characteristics with respect to this stress is greatly influenced by the surface residual stress of the shaft, and it is necessary to make the surface residual stress uniform. Therefore, in general, the shaft material for a torque sensor is subjected to carburizing treatment, and then subjected to heat treatment such as quenching such as tempering and sub-zero treatment, and mechanical stress load such as shot peening to reduce the surface residual stress. Are made uniform to improve the magnetic characteristics. In addition, JP-A-60
As disclosed in Japanese Patent Publication No. 254678, a surface compressive stress is applied to a shaft material to improve fatigue strength and magnetic characteristics.
【０００４】[0004]
【発明が解決しようとする課題】ところが、浸炭鋼を焼
入れ、焼もどし、サブゼロ処理などの熱処理した場合、
オーステナイトがマルテンサイト化して硬度が高くなり
すぎ、靱性が低下して脆くなる問題がある。また、浸炭
処理の際に生じた表面の酸化物層は、軸の疲労強度を低
下させる。すなわち、軸材の表面に生じた酸化物層は、
従来、センサとして使用する場合なんら考慮が払われて
おらず、無視されていた。ところが、発明者等の研究に
よると、軸材の表面の酸化物層、特に粒界／粒界層が酸
化した場合には、軸の強度を低下させ、また磁気特性の
ヒステリシスの大きな原因になっていることが判明し
た。しかも、この酸化物層は、ショットピーニングなど
の機械的応力付加を行っても除去することが難しい。However, when the carburized steel is hardened, tempered, or subjected to heat treatment such as sub-zero treatment,
There is a problem that austenite becomes martensite and the hardness becomes too high, and the toughness decreases and becomes brittle. Further, the oxide layer on the surface generated during the carburizing treatment reduces the fatigue strength of the shaft. That is, the oxide layer generated on the surface of the shaft is
Conventionally, no consideration was given to the use as a sensor, and it was ignored. However, according to the research conducted by the inventors, when the oxide layer on the surface of the shaft material, particularly the grain boundary / grain boundary layer, is oxidized, the strength of the shaft is lowered, and it becomes a major cause of hysteresis of magnetic properties. It turned out. Moreover, it is difficult to remove this oxide layer even if mechanical stress such as shot peening is applied.
【０００５】また、軸材の表面に圧縮応力を作ること
は、特開昭６０−２５４６７８号公報に記載の如く、焼
入れ加工時に表面圧縮むらが大きいと、センサ出力が不
安定となる。そして、軸材に大きな応力を付加して残留
応力の均一化をすることも有用であるが、大型の構造物
には適していない。Further, as described in JP-A-60-254678, when a compressive stress is created on the surface of the shaft material, if the surface compression unevenness is large during quenching, the sensor output becomes unstable. It is also useful to apply a large stress to the shaft material to make the residual stress uniform, but it is not suitable for a large structure.
【０００６】一方、浸炭処理後の熱処理による靱性の低
下を避けるために、浸炭において炭素量を多くすると、
高炭素になるほど非磁性体である残留オーステナイト量
（残留γ量）が多くなって磁気特性が低下する。しか
も、残留オーステナイトが多くなると、軸材の硬度、剛
性などが低下し、軸強度、疲労強度に影響してくる。と
なる。従って、軸材は、表面に適度の残留オーステナイ
ト量を有していて、大きな硬さや剛性、疲労強度を有し
ていることが望まれる。On the other hand, in order to avoid a decrease in toughness due to heat treatment after carburizing, if the amount of carbon in carburizing is increased,
The higher the carbon content, the greater the amount of retained austenite, which is a non-magnetic substance, (retained γ amount), and the magnetic properties deteriorate. Moreover, when the amount of retained austenite increases, the hardness and rigidity of the shaft material decrease, which affects the shaft strength and fatigue strength. Becomes Therefore, it is desired that the shaft material has an appropriate amount of retained austenite on the surface and has large hardness, rigidity, and fatigue strength.
【０００７】また、高Ｎｉ鋼のように浸炭後の焼入れ性
が悪い材料においては、昔からサブゼロ処理、ショット
ピーニングなどにより表面残留オーステナイト量の調整
（減少）を行っている。しかし、サブゼロ処理を行う
と、表面近傍から浸炭層の内部深くまでマルテンサイト
化が進み、残留γ量が減少しすぎて疲労強度の低下が避
けられない。表面にある酸化物層による強度劣化は、残
留オーステナイトのマルテンサイトへの変態によって補
っていると考えられる。そこで、軸材の残留γ量は、最
表面近傍において１０％程度に減少させ、その下部にお
いて多少多めにする処理が期待させる。Further, in the case of a material such as a high Ni steel which has a poor hardenability after carburization, the amount of retained austenite on the surface has been adjusted (reduced) by subzero treatment, shot peening, etc. for a long time. However, when the sub-zero treatment is performed, martensite formation progresses from near the surface to deep inside the carburized layer, and the amount of residual γ decreases too much, so that a decrease in fatigue strength cannot be avoided. It is considered that the strength deterioration due to the oxide layer on the surface is compensated by the transformation of retained austenite into martensite. Therefore, it is expected that the residual γ amount of the shaft material will be reduced to about 10% in the vicinity of the outermost surface and slightly increased in the lower portion.
【０００８】ところで、ショットピーニング処理をする
場合には、建設機械に用いるような大型構造物に均一に
当てることが困難で、処理にむらを生ずる。しかも、大
型構造物は、サブゼロ処理またはショットピーニング等
を行う場合、均一な処理が困難であるばかりでなく、処
理設備が大型となり、多くの設備費用が必要となり、コ
ストの上昇要因となる。このため、トルク検出用の軸材
の浸炭処理は、疲労強度を有するとともに、センサとし
ての磁気特性に優れたものが得られることが望ましい。By the way, when the shot peening process is performed, it is difficult to uniformly apply it to a large structure such as used in a construction machine, which causes unevenness in the process. In addition, in the case of performing a sub-zero treatment or shot peening on a large structure, not only is it difficult to perform uniform treatment, but also the treatment equipment becomes large and a large amount of equipment cost is required, which causes a cost increase. Therefore, it is desirable that the carburizing treatment of the shaft material for torque detection has fatigue strength and excellent magnetic characteristics as a sensor.
【０００９】本発明は、上記従来技術の欠点を解消する
ためになされたもので、疲労強度に優れ、また応力に対
する磁気特性に優れたトルク検出軸の製造方法を提供す
ることを目的としている。The present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a method of manufacturing a torque detection shaft having excellent fatigue strength and magnetic characteristics against stress.
【００１０】[0010]
【課題を解決するための手段および作用】上記の目的を
達成するために、本発明に係るトルク検出軸の製造方法
は、浸炭処理をする際に、浸炭用のガス（例えば、ＣＯ
2 、ＣＯ、Ｈ2 、Ｈ2 Ｏ、ＣＨ4、ＮＨ3 、Ｎ2 、Ａｒ
等とプロパンなどの炭化水素との混合ガスからなる吸熱
形変成ガス）の組成を調整し、このガスの平衡炭素濃度
（カーボンポテンシャル）を通常使われている０．７〜
０．８％から０．６％前後以下にして浸炭する。これに
より、浸炭後の軸材表面の炭素量は０．７５重量％以下
なり（大半は０．７重量％程度）、残留オーステナイト
が減少して磁気特性が向上する。しかも、軸材の表面直
下部には、残留γが存在して疲労強度の向上に寄与して
いる。なお、浸炭深さは、軸材が建設機械に使用する大
型構造物である場合、２ｍｍ以上とすることが望まし
い。また、低合金構造鋼としては、ＪＩＳのＳＮＣＭ２
２０、ＳＮＣＭ６３０、ＳＮＣＭ８１５等のいやゆる肌
焼き鋼を用いることができる。In order to achieve the above-mentioned object, the method for manufacturing a torque detecting shaft according to the present invention has a carburizing gas (for example, CO
2 , CO, H 2 , H 2 O, CH 4 , NH 3 , N 2 , Ar
Etc. and an endothermic metamorphic gas consisting of a mixed gas of hydrocarbons such as propane) is adjusted, and the equilibrium carbon concentration (carbon potential) of this gas is usually 0.7-
Carburize from 0.8% to around 0.6% or less. As a result, the amount of carbon on the surface of the shaft material after carburization becomes 0.75 wt% or less (most are about 0.7 wt%), the retained austenite is reduced, and the magnetic properties are improved. Moreover, the residual γ exists just below the surface of the shaft member, which contributes to the improvement of fatigue strength. The carburizing depth is preferably 2 mm or more when the shaft material is a large structure used in a construction machine. Also, as a low alloy structural steel, JIS SNCM2
No. 20, SNCM 630, SNCM 815, etc. can be used.
【００１１】また、本発明においては、通常の浸炭処理
または高炭素浸炭処理をした軸材を再焼入れし、軸材の
表面炭素を脱炭または炭化物として析出させ、軸材表面
の炭素濃度を０．７５重量％以下にして残留オーステナ
イト量を減少させ、磁気特性の向上と疲労強度の向上を
図る。Further, in the present invention, the shaft material which has been subjected to the ordinary carburizing treatment or the high carbon carburizing treatment is re-quenched, and the surface carbon of the shaft material is decarburized or precipitated as a carbide so that the carbon concentration on the surface of the shaft material is 0. The amount of retained austenite is reduced to 0.75% by weight or less to improve magnetic properties and fatigue strength.
【００１２】再焼入れの温度は、オーステナイト領域で
ある８５０℃以下にする。焼入れ温度があまり高いと炭
素が再固溶し、軸材中の炭素量が増加して残留オーステ
ナイトを増加させることになり、逆効果となる。従っ
て、再焼入れの加熱温度は、加熱保持時間とともに、軸
材の鋼種、軸径を考慮して決定する。The re-quenching temperature is set to 850 ° C. or lower which is in the austenite region. If the quenching temperature is too high, carbon is re-dissolved, the amount of carbon in the shaft material increases, and the retained austenite increases, which has the opposite effect. Therefore, the heating temperature for re-quenching is determined in consideration of the steel type and the shaft diameter of the shaft material together with the heating and holding time.
【００１３】さらに、本発明においては、浸炭処理をし
た軸材を焼入れ、焼もどしまたはサブゼロ処理等の熱処
理を行ったのち、軸材の表面を研磨し、浸炭処理や熱処
理に伴って生じた軸材表面の酸化物層を除去し、酸化物
層による軸材の強度の低下を阻止するとともに、磁気ヒ
ステリシスの向上を図る。研磨量は、浸炭処理時間の長
さ、浸炭処理後の熱処理時間の長さによって異なり、軸
材が例えば建設機械などに使用する処理時間の長い大型
構造物である場合、５０μｍ程度である。Further, in the present invention, after the carburized shaft material is subjected to heat treatment such as quenching, tempering or sub-zero treatment, the surface of the shaft material is polished and the shaft produced by the carburizing treatment or heat treatment. The oxide layer on the surface of the material is removed to prevent the reduction of the strength of the shaft material due to the oxide layer and to improve the magnetic hysteresis. The polishing amount varies depending on the length of the carburizing treatment time and the length of the heat treating time after the carburizing treatment, and is about 50 μm when the shaft material is a large structure used for construction machines for a long treatment time.
【００１４】なお、軸材の表面研磨は、残留応力が均一
となるように、冷却しながらゆっくりと加工することが
望ましい。これは、トルク検出部となる検出軸の表面
は、平滑で表面残留応力が均一であることが最も大切で
あることによる。また、機械的加工処理としては、ロー
ル、ショットピーニングでよい。In the surface polishing of the shaft material, it is desirable to process slowly while cooling so that the residual stress becomes uniform. This is because it is most important that the surface of the detection shaft that serves as the torque detection unit be smooth and have a uniform surface residual stress. The mechanical processing may be roll or shot peening.
【００１５】[0015]
【実施例】以下、本発明に係るトルク検出軸の製造方法
の好ましい実施例を詳説する。まず、軸材として低合金
構造鋼であるＪＩＳ ＳＮＣＭ２２０を用い、このＳＮ
ＣＭ２２０からなる図１に示した円柱状の軸１０に標準
的な浸炭処理をし、軸１０のトルクに対する磁気ヒステ
リシスを計測した。すなわち、ＳＮＣＭ２２０をカーボ
ンポテンシャルが０．７〜０．８％のガス雰囲気中にお
いて９３０°Ｃに加熱し、約１時間ガス浸炭を行った。
その後、雰囲気を焼入れ温度である８４０°Ｃに下げ、
この温度で３０分保持してから油焼入れを行った。次
に、焼入れした軸１０を１７０°Ｃに加熱して２時間保
持したのち、空冷して焼もどしを行った。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a method for manufacturing a torque detecting shaft according to the present invention will be described in detail below. First, JIS SNCM220, which is a low alloy structural steel, is used as the shaft material.
The cylindrical shaft 10 shown in FIG. 1 made of CM220 was subjected to standard carburizing treatment, and the magnetic hysteresis with respect to the torque of the shaft 10 was measured. That is, SNCM220 was heated to 930 ° C. in a gas atmosphere having a carbon potential of 0.7 to 0.8%, and gas carburization was performed for about 1 hour.
After that, the atmosphere is lowered to the quenching temperature of 840 ° C,
Oil quenching was performed after holding at this temperature for 30 minutes. Next, the quenched shaft 10 was heated to 170 ° C. and held for 2 hours, and then air-cooled to perform tempering.
【００１６】さらに、焼もどしをした軸１０に、長手方
向に沿って４つの磁気異方性部１２ａ〜１２ｄを設けて
トルク検出軸とした。この磁気異方性部１２ａ〜１２ｄ
は、軸１０の軸線に対して４５度傾斜させたせた螺旋上
の溝１４を設けることによって形成してあり、溝１４は
幅１ｍｍで深さ１ミリであって、１ミリピッチで形成し
てある。このようにして磁気異方性部１２ａ〜１２ｄを
設けた軸１０の周囲に検出コイル１６を配置し、軸１０
に作用するトルクに対する磁気ヒステリシスを計測した
ところ、図２の結果が得られた。なお、各磁気異方性部
１２ａ〜１２ｄの長さはそれぞれ１０ｍｍであり、各検
出コイル１６の長さはそれぞれ８ｍｍである。Further, the tempered shaft 10 is provided with four magnetic anisotropic portions 12a to 12d along the longitudinal direction to form a torque detecting shaft. The magnetic anisotropic portions 12a to 12d
Is formed by providing a spiral groove 14 inclined 45 degrees with respect to the axis of the shaft 10. The groove 14 has a width of 1 mm, a depth of 1 mm, and is formed at a pitch of 1 mm. .. In this way, the detection coil 16 is arranged around the shaft 10 provided with the magnetic anisotropic portions 12a to 12d.
When the magnetic hysteresis with respect to the torque acting on was measured, the results shown in FIG. 2 were obtained. The magnetic anisotropic portions 12a to 12d each have a length of 10 mm, and each detection coil 16 has a length of 8 mm.
【００１７】また、図１に示した軸１０の表面を約５０
μｍ研磨して軸表面の酸化物層を除去し、図１と同様に
して軸１０のトルクに対する磁気ヒステリシスを求めた
ところ、図３に示す結果が得られた。すなわち、軸材を
浸炭処理後、焼入れ、焼もどしの熱処理をしたのち、こ
れら浸炭処理、熱処理によって生じた酸化物層を研磨し
て除去すると、磁気特性を著しく向上させることができ
る。The surface of the shaft 10 shown in FIG.
When the oxide layer on the surface of the shaft was removed by polishing to a thickness of μm and the magnetic hysteresis with respect to the torque of the shaft 10 was obtained in the same manner as in FIG. 1, the results shown in FIG. 3 were obtained. That is, when the shaft material is carburized, then heat treated for quenching and tempering, and then the oxide layer produced by the carburizing and heat treatment is polished and removed, the magnetic characteristics can be remarkably improved.
【００１８】次に、ＪＩＳ ＳＮＣＭ２２０からなる軸
材を、ガスのカーボンポテンシャルを０．６５％となる
ように設定し、上記と同様にして浸炭処理、焼入れ、焼
もどしを行い、トルク検出軸にしてトルクに対する磁気
ヒステリシスを求めたところ、図４に示した結果が得ら
れ、通常のカーボンポテンシャルが０．７５〜８．０％
で浸炭処理をした場合よりも磁気特性を向上させること
ができた。なお、このときの軸１０の表面部分の残留オ
ーステナイト量は約１０％で、通常の浸炭処理の場合の
約２０％より大きく低下していた。Next, the shaft material made of JIS SNCM220 was set so that the carbon potential of the gas would be 0.65%, and carburizing, quenching, and tempering were performed in the same manner as above, and the shaft was used as the torque detection shaft. When the magnetic hysteresis with respect to the torque was obtained, the results shown in FIG. 4 were obtained, and the normal carbon potential was 0.75 to 8.0%.
It was possible to improve the magnetic properties as compared with the case where the carburizing treatment was carried out at. The amount of retained austenite on the surface portion of the shaft 10 at this time was about 10%, which was much lower than about 20% in the case of the ordinary carburizing treatment.
【００１９】また、ＪＩＳ ＳＮＣＭ２２０からなる軸
材を、前記の如く通常の浸炭処理、焼入れ、焼もどしを
したのち、８５０°Ｃに加熱して軸材の表面炭素の脱
炭、炭化物化をして表面炭素量を０．７重量％以下に
し、再焼入れをしたのちトルク検出軸に形成してトルク
に対する磁気ヒステリシスを測定してところ、図５に示
す結果が得られ、通常の処理に比較して磁気特性を向上
することができた。Further, the shaft material made of JIS SNCM220 is carburized, quenched and tempered as described above, and then heated to 850 ° C. to decarburize and carbonize the surface carbon of the shaft material. The surface carbon content was 0.7% by weight or less, and after re-quenching, it was formed on the torque detection shaft and the magnetic hysteresis with respect to the torque was measured. The results shown in FIG. 5 were obtained. The magnetic characteristics could be improved.
【００２０】なお、前記実施例においては、浸炭処理と
浸炭処理後の熱処理のみを行った場合について説明した
が、浸炭後の熱処理を行った後、ショットピーニングや
ロールなどの機械的加工処理をおこなってもよい。そし
て、浸炭処理、熱処理によって発生した酸化物層を研磨
して除去する場合、熱処理直後に行ってもよいし、ショ
ットピーニングなどの機械的加工処理をした後に行って
もよい。また、浸炭後の熱処理としてサブゼロ処理を行
ってもよい。In the above embodiment, the case where only the carburizing treatment and the heat treatment after the carburizing treatment were performed was explained. However, after the heat treatment after carburizing, mechanical processing treatment such as shot peening and rolls is performed. May be. When the oxide layer generated by the carburizing treatment or the heat treatment is removed by polishing, the oxide layer may be removed immediately after the heat treatment or after mechanical processing such as shot peening. Further, a sub-zero treatment may be performed as a heat treatment after carburizing.
【００２１】[0021]
【発明の効果】以上に説明したように、本発明によれ
ば、浸炭処理用ガスの組成を調整して、浸炭後の軸材表
面の炭素量を０．７５重量％以下にすることにより、疲
労強度と磁気特性に優れたトルク検出軸を得ることがで
きる。As described above, according to the present invention, the composition of the carburizing gas is adjusted so that the carbon content on the surface of the shaft material after carburization is 0.75% by weight or less. It is possible to obtain a torque detection shaft having excellent fatigue strength and magnetic properties.
【００２２】また、本発明においては、通常の浸炭処理
または高炭素浸炭処理をした軸材を再焼入れし、軸材の
表面炭素を脱炭または炭化物として析出させ、軸材表面
の炭素濃度を０．７５重量％以下とすることにより、上
記と同様の効果が得られる。さらに、本発明において
は、浸炭処理をした軸材を焼入れ、焼もどしまたはサブ
ゼロ処理等の熱処理を行ったのち軸材の表面を研磨し
て、浸炭処理や熱処理に伴って生じた軸材表面の酸化物
層を除去することにより、酸化物層による軸材の強度の
低下が阻止できるとともに、磁気ヒステリシスの向上を
図ることができる。Further, in the present invention, the shaft material which has been subjected to the ordinary carburizing treatment or the high carbon carburizing treatment is re-quenched so that the surface carbon of the shaft material is decarburized or precipitated as a carbide so that the carbon concentration on the surface of the shaft material is 0. By setting the content to 0.75% by weight or less, the same effect as described above can be obtained. Further, in the present invention, quenching the carburized shaft material, after performing heat treatment such as tempering or sub-zero treatment, the surface of the shaft material is polished, and the surface of the shaft material produced by the carburizing treatment or heat treatment is By removing the oxide layer, it is possible to prevent a decrease in the strength of the shaft material due to the oxide layer and to improve the magnetic hysteresis.
【図１】トルク検出軸のトルクに対する磁気ヒステリシ
スを計測する方法の説明図である。FIG. 1 is an explanatory diagram of a method of measuring magnetic hysteresis with respect to torque of a torque detection shaft.
【図２】従来の浸炭処理と熱処理とをしたトルク検出軸
のトルクに対する磁気ヒステリシスを示す図である。FIG. 2 is a diagram showing the magnetic hysteresis with respect to the torque of the torque detection shaft that has been subjected to the conventional carburizing treatment and heat treatment.
【図３】従来の浸炭処理と熱処理とをしたのち、軸の表
面を研磨して酸化物層を除去した実施例のトルクに対す
る磁気ヒステリシスを示す図である。FIG. 3 is a diagram showing magnetic hysteresis with respect to torque in an example in which the surface of the shaft was polished and the oxide layer was removed after the conventional carburizing treatment and heat treatment.
【図４】浸炭用ガスの組成を調整して軸材の表面炭素量
を０．７重量％以下にした実施例のトルクに対する磁気
ヒステリシスを示す図である。FIG. 4 is a diagram showing magnetic hysteresis with respect to torque in an example in which the composition of the carburizing gas is adjusted so that the surface carbon content of the shaft material is 0.7% by weight or less.
【図５】通常の浸炭処理をしたのち、再焼入れをして軸
材の表面炭素量を０．７重量％以下にした実施例のトル
クに対する磁気ヒステリシスを示す図である。FIG. 5 is a diagram showing magnetic hysteresis with respect to torque in an example in which the surface carbon content of the shaft material was reduced to 0.7% by weight or less by performing normal carburizing treatment and then re-quenching.
Claims (6)
炭処理して硬化するトルク検出軸の製造方法において、
浸炭処理用ガスの組成を調整し、前記浸炭処理後におけ
る前記軸材表面の炭素量を０．７５重量％以下にするこ
とを特徴とするトルク検出軸の製造方法。1. A method of manufacturing a torque detecting shaft, wherein a surface of a shaft material made of low alloy structural steel is carburized and hardened,
A method for producing a torque detecting shaft, wherein the composition of the carburizing gas is adjusted so that the carbon content on the surface of the shaft material after the carburizing process is 0.75 wt% or less.
炭処理して硬化するトルク検出軸の製造方法において、
前記浸炭処理後に再焼入れ処理をし、前記軸材表面の炭
素量を０．７５重量％以下にして表面残留オーステナイ
ト量の低減と表面残留応力の調整とをすることを特徴と
するトルク検出軸の製造方法。2. A method for manufacturing a torque detecting shaft, wherein a surface of a shaft material made of low alloy structural steel is carburized and hardened,
A re-quenching treatment is performed after the carburizing treatment to reduce the amount of carbon on the surface of the shaft material to 0.75% by weight or less to reduce the amount of surface retained austenite and adjust the surface residual stress. Production method.
炭処理して硬化するトルク検出軸の製造方法において、
前記浸炭処理後に焼入れ、焼もどし、サブゼロ処理等の
熱処理をしたのち、前記軸材の表面を研磨して前記浸炭
処理と前記熱処理とによって生じた酸化物層を除去する
ことを特徴とするトルク検出軸の製造方法。3. A method of manufacturing a torque detecting shaft, wherein a surface of a shaft material made of low alloy structural steel is carburized and hardened,
After the carburizing treatment, after the heat treatment such as quenching, tempering, and sub-zero treatment, the surface of the shaft material is polished to remove the oxide layer generated by the carburizing treatment and the heat treatment. Shaft manufacturing method.
炭処理して硬化するトルク検出軸の製造方法において、
前記浸炭処理後に焼入れ、焼もどし、サブゼロ処理等の
熱処理と機械的加工処理とをし、その後、前記軸材の表
面を研磨して前記浸炭処理と前記熱処理とによって生じ
た酸化物層を除去することを特徴とするトルク検出軸の
製造方法。4. A method for manufacturing a torque detecting shaft, comprising carburizing and hardening the surface of a shaft material made of low alloy structural steel,
After the carburizing treatment, heat treatment such as quenching, tempering, and sub-zero treatment and mechanical working treatment are performed, and then the surface of the shaft material is polished to remove the oxide layer generated by the carburizing treatment and the heat treatment. A method for manufacturing a torque detection shaft, comprising:
炭処理して硬化するトルク検出軸の製造方法において、
前記浸炭処理後に焼入れ、焼もどし、サブゼロ処理等の
熱処理をしたのち、前記軸材の機械的加工処理の前また
は後に、前記軸材の表面を研磨して前記浸炭処理と前記
熱処理とによって生じた酸化物層を除去し、軸材表面の
残留圧縮応力を均一に低減させることを特徴とするトル
ク検出軸の製造方法。5. A method for manufacturing a torque detecting shaft, wherein a surface of a shaft material made of low alloy structural steel is carburized and hardened,
After heat treatment such as quenching, tempering, and sub-zero treatment after the carburizing treatment, before or after the mechanical processing treatment of the shaft material, the surface of the shaft material is polished to cause the carburizing treatment and the heat treatment. A method for manufacturing a torque detection shaft, comprising removing an oxide layer to uniformly reduce residual compressive stress on the surface of a shaft material.
炭処理して硬化するトルク検出軸の製造方法において、
前記浸炭処理後に焼入れ、焼もどし、サブゼロ処理等の
熱処理および機械的加工処理により前記軸材の表面残留
オーステナイト量を低減するとともに、前記機械的加工
処理の前または後に、前記軸材の表面を研磨して前記浸
炭処理と前記熱処理とによって生じた酸化物層を除去
し、軸材表面の残留圧縮応力を均一に低減させることを
特徴とするトルク検出軸の製造方法。6. A method for manufacturing a torque detecting shaft, comprising carburizing and hardening the surface of a shaft material made of low alloy structural steel,
After the carburizing treatment, quenching, tempering, heat treatment such as sub-zero treatment and mechanical processing treatment reduce the amount of retained austenite on the surface of the shaft material, and polish the surface of the shaft material before or after the mechanical processing treatment. Then, the oxide layer generated by the carburizing treatment and the heat treatment is removed to uniformly reduce the residual compressive stress on the surface of the shaft material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04056982A JP3095864B2 (en) | 1992-02-07 | 1992-02-07 | Manufacturing method of torque detection shaft |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04056982A JP3095864B2 (en) | 1992-02-07 | 1992-02-07 | Manufacturing method of torque detection shaft |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05223663A true JPH05223663A (en) | 1993-08-31 |
| JP3095864B2 JP3095864B2 (en) | 2000-10-10 |
Family
ID=13042714
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04056982A Expired - Fee Related JP3095864B2 (en) | 1992-02-07 | 1992-02-07 | Manufacturing method of torque detection shaft |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3095864B2 (en) |
-
1992
- 1992-02-07 JP JP04056982A patent/JP3095864B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP3095864B2 (en) | 2000-10-10 |
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