JPH05169324A - High strength hypoid gear - Google Patents
High strength hypoid gearInfo
- Publication number
- JPH05169324A JPH05169324A JP35589291A JP35589291A JPH05169324A JP H05169324 A JPH05169324 A JP H05169324A JP 35589291 A JP35589291 A JP 35589291A JP 35589291 A JP35589291 A JP 35589291A JP H05169324 A JPH05169324 A JP H05169324A
- Authority
- JP
- Japan
- Prior art keywords
- tooth
- fatigue strength
- bearing
- conventional example
- ring gear
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Gear Processing (AREA)
- Gears, Cams (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は自動車の動力伝達装置で
ある減速歯車に関し、特にハイポイド歯車に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reduction gear which is a power transmission device for an automobile, and more particularly to a hypoid gear.
【０００２】[0002]
【従来の技術】減速歯車はプロペラシャフトからの回転
動力を受けるドライブピニオンとこれに直角に交わり減
速を行うリングギヤから構成されるが、その中でもハイ
ポイド歯車はリングギヤとドライブピニオンの中心を偏
心したものであって、大きな駆動力を伝えることができ
る。2. Description of the Related Art A reduction gear is composed of a drive pinion that receives rotational power from a propeller shaft and a ring gear that crosses at right angles to the drive pinion to reduce the speed. Among them, a hypoid gear is one in which the center of the ring gear and the drive pinion are eccentric. Therefore, it can transmit a large driving force.
【０００３】これら自動車の動力伝達用の歯車は、高強
度が要求され、焼入れ処理、特に浸炭焼入れ処理が施さ
れて使用されている。これにより硬さが高く、圧縮の残
留応力を有する浸炭焼入れ層が形成され、その両者の作
用によって疲労強度が向上すると言われている。These gears for power transmission of automobiles are required to have high strength and are used after being subjected to quenching treatment, particularly carburizing and quenching treatment. As a result, a carburized and quenched layer having high hardness and residual stress of compression is formed, and it is said that the fatigue strength is improved by the action of both of them.
【０００４】然るに、最近機械装置の高性能化に伴い、
構成部品は高速、高負荷の苛酷な条件で使用されるよう
になっており、このため部品の強度を高めることが産業
界で要求されている。特に自動車産業においては、燃費
向上を目的とした車両軽量化が重要課題となっており、
そのため、各種部品の高強度化技術の開発が強く求めら
れている。However, with the recent increase in the performance of mechanical devices,
Since the component parts are used under high-speed, high-load and severe conditions, it is required in the industry to increase the strength of the component parts. Particularly in the automobile industry, weight reduction of vehicles for the purpose of improving fuel efficiency has become an important issue.
Therefore, development of technology for strengthening various parts is strongly demanded.
【０００５】そのため、自動車の動力伝達用の歯車にお
いても、前記の浸炭焼入れ処理に加えて、ショットピー
ニング処理を付加することが多くなっている。ショット
ピーニングは金属部品の疲れ強さの向上を目的として比
較的球形に近い鉄の粒子を高速度で部品の表面に衝突さ
せる表面処理方法である。このショットピーニング処理
は、鋼部材の表面下２００〜４００μｍにわたって大き
な圧縮残留応力が付与されるため、疲労強度が向上する
と言われている。Therefore, in addition to the carburizing and quenching treatment, shot peening treatment is often added to the gear for power transmission of automobiles. Shot peening is a surface treatment method in which relatively spherical spherical iron particles are made to collide with the surface of the component at high speed in order to improve the fatigue strength of the metal component. It is said that this shot peening treatment improves fatigue strength because a large compressive residual stress is applied over 200 to 400 μm below the surface of the steel member.
【０００６】しかしながら、このショットピーニングに
より鋼部材に発生する残留応力は、表面下１０〜１００
μｍ内部の位置でピークを有し、より表面層では、圧縮
応力値が小さいという基本的な特性を有する。また、シ
ョットピーニングは、硬質粒子を高速で衝突させるた
め、部材の表面に疵が生じ易い。However, the residual stress generated in the steel member by this shot peening is 10-100 below the surface.
It has a basic characteristic that it has a peak at a position inside μm, and the surface layer has a smaller compressive stress value. In addition, since shot peening causes hard particles to collide at high speed, flaws are likely to occur on the surface of the member.
【０００７】さらに、鋼部材が浸炭焼入れの場合には、
表面から５〜５０μｍにわたって浸炭異常層と呼ばれる
不完全焼入れ層が存在する。この低強度の異常層はショ
ットピーニング処理によっても除去されず残留するた
め、表面疵等とともに疲労破壊の起点になりやすく、安
定かつ大幅な疲労強度の向上は望めないのが実情であ
る。Further, when the steel member is carburized and quenched,
There is an incompletely hardened layer called a carburized abnormal layer extending from 5 to 50 μm from the surface. Since the abnormal layer of low strength remains without being removed even by the shot peening treatment, it easily becomes a starting point of fatigue fracture along with surface flaws, etc., and it is the actual situation that stable and significant improvement of fatigue strength cannot be expected.
【０００８】これらの従来技術の問題点を解決する方法
として、疲労強度の向上を阻害している前記表面層を除
去するために、表面硬化処理を行った後ショットピーニ
ングを行い、さらに立方晶窒化ホウ素ホイールで研削加
工して仕上歯切を行う「高強度歯車の製造方法」（特開
平１−２６４７２７号）等の機械的研磨法が提案されて
いる。As a method of solving these problems of the prior art, in order to remove the surface layer which hinders the improvement of fatigue strength, a surface hardening treatment is performed followed by shot peening, and further cubic nitriding. Mechanical polishing methods have been proposed, such as "High-strength gear manufacturing method" (Japanese Patent Laid-Open No. 1-264727) in which a boron wheel is ground to finish gear cutting.
【０００９】[0009]
【発明が解決しようとする課題】疲労強度の観点から欠
陥を有する表面層を除去し、かつできるだけ平滑な仕上
げ面とすることが要求されるが、前記提案のような機械
的研磨方法では焼入れ鋼部材の硬さが高いため研削仕上
げの加工効率が大変低い。特に、歯車等の形状が複雑な
部品の場合には、疲労強度向上が問題となる歯元部をよ
く研磨しようとすると加工効率が著しく低下するという
問題がある。From the viewpoint of fatigue strength, it is required to remove the surface layer having defects and to make the finished surface as smooth as possible. However, in the mechanical polishing method as proposed above, hardened steel is used. Since the hardness of the member is high, the processing efficiency of grinding finish is very low. In particular, in the case of a component such as a gear having a complicated shape, there is a problem in that the machining efficiency is remarkably lowered if the root portion of the tooth, which is problematic in improving the fatigue strength, is well ground.
【００１０】かかる問題点を解決するため、発明者等は
先の出願（特願平２−３２８１９０）において、ショッ
トピーニングを施した鋼部材の表面を化学研磨する鋼部
材の疲労強度向上方法を提案している。この提案におい
ては、従来技術のような機械的研磨あるいは電解研磨の
ように特別な外部からの作用ではなく、化学研磨処理液
が有する化学的な溶解力に基づいているため、化学研磨
処理液と接する被処理材表面では材料の硬さおよび形状
によらず均一な研磨が進行する。In order to solve such a problem, the inventors of the present invention proposed a method for improving the fatigue strength of a steel member in the prior application (Japanese Patent Application No. 2-328190) by chemically polishing the surface of the steel member subjected to shot peening. is doing. In this proposal, since it is based on the chemical dissolving power of the chemical polishing treatment liquid rather than a special external action such as mechanical polishing or electrolytic polishing as in the prior art, Uniform polishing proceeds on the surface of the material to be contacted, regardless of the hardness and shape of the material.
【００１１】その結果、ショットピーニング工程後に存
在する疲労破壊の原因になりやすい各種欠陥の研磨除去
が完全に行われ、部分的な取り残しをなくすことができ
る。また、この化学研磨処理後の鋼表面は、化学研磨作
用により著しい平滑化がなされるため、疲労破壊の起点
部での応力集中が緩和され、大幅かつ安定した疲労強度
の向上が可能となる。As a result, various defects that tend to cause fatigue fracture existing after the shot peening process are completely removed by polishing, and a partial residue can be eliminated. Further, since the steel surface after the chemical polishing treatment is significantly smoothed by the chemical polishing action, stress concentration at the starting point of fatigue fracture is relieved, and it is possible to significantly and stably improve the fatigue strength.
【００１２】このように、浸炭処理を施した後ショット
ピーニングを行い、さらに化学研磨処理を行うという前
記提案においては、鋼部材の最表面は極めて高硬度、高
圧縮残留応力、しかも良好な表面状態（面粗度良好、浸
炭異常層なし）が得られるので、極めて高い疲労強度が
得られる。従って、この提案は部品の軽量設計をする上
で有効な手段であると考えられる。As described above, in the above-mentioned proposal that the shot peening is performed after the carburizing treatment and the chemical polishing treatment is further performed, the outermost surface of the steel member has extremely high hardness, high compressive residual stress, and a good surface condition. (Good surface roughness, no abnormal carburizing layer) is obtained, so extremely high fatigue strength is obtained. Therefore, this proposal is considered to be an effective means for designing lightweight parts.
【００１３】そこで、発明者等は、前記提案を自動車用
ディファレンシャルの疲労強度を高めるため、その構成
部品であるハイポイドギヤ対に適用を試みた。表２は自
動車ディファレンシャルのユニット状態で一定のトルク
を入力し、破損までの繰り返し数を比較したもので、従
来例１は浸炭後ショットピーニングを施したもの、従来
例２はそれにさらに化学研磨処理を追加したものであ
る。Therefore, the inventors have tried to apply the above-mentioned proposal to a hypoid gear pair, which is a component thereof, in order to enhance the fatigue strength of a differential for an automobile. Table 2 is a comparison of the number of repetitions until a certain torque is input in a vehicle differential unit state, where Conventional Example 1 is carburized and shot peened, and Conventional Example 2 is further chemically polished. It was added.
【００１４】ところが、表２に示したように、従来例２
はショットピーニング後化学研磨を施すことにより、大
幅な疲労強度の向上が期待されたにもかかわらず、破損
に到るまでの寿命は、従来例１の７９万回に対して従来
例２は５０万回であって、ユニット状態での耐久試験に
おいて疲労強度が逆に低下している。However, as shown in Table 2, the conventional example 2
Although it is expected that the fatigue strength will be greatly improved by performing chemical polishing after shot peening, the life until damage is 790,000 times in Conventional Example 1 and 50 in Conventional Example 2. However, the fatigue strength was decreased in the durability test in the unit state.
【００１５】本発明は浸炭処理を施した後ショットピー
ニングを行い、さらに化学研磨処理を行ったハイポイド
ギヤ対が、浸炭処理を施した後ショットピーニングを行
っただけのハイポイドギヤ対よりも疲労強度において劣
るという前記のごとき問題点を解決すべくなされたもの
であって、浸炭処理を施した後ショットピーニングを行
い、さらに化学研磨処理を施すことにより、従来よりも
さらに疲労強度に優れた高強度ハイポイド歯車を提供す
ることを目的とする。According to the present invention, the hypoid gear pair which is carburized and then shot peened and chemically polished is inferior in fatigue strength to the hypoid gear pair which is carburized and then shot peened. A high-strength hypoid gear that is more excellent in fatigue strength than before by being subjected to carburizing treatment, shot peening, and chemical polishing treatment. The purpose is to provide.
【００１６】[0016]
【課題を解決するための手段】発明者等は、先ず化学研
磨処理を行ったハイポイドギヤ対が、何故疲労強度に劣
るのか、その原因を追求するため、ユニット状態で疲労
強度評価を行った従来例１および従来例２のハイポイド
ギヤ対の破壊面の観察を行った。図２は従来例１のリン
グギヤの破壊面の模写図、図３は従来例２のリングギヤ
の破壊面の模写図である。Means for Solving the Problems The inventors of the present invention first performed a fatigue strength evaluation in a unit state in order to investigate the reason why the hypoid gear pair subjected to the chemical polishing treatment is inferior in fatigue strength, and a conventional example. The fracture surfaces of the hypoid gear pairs of Example 1 and Conventional Example 2 were observed. FIG. 2 is a copy diagram of the fracture surface of the ring gear of Conventional Example 1, and FIG. 3 is a copy diagram of the fracture surface of the ring gear of Conventional Example 2.
【００１７】これらの破壊面から１次破損部位を特定す
ることは容易でないが、本発明者等はマクロおよびミク
ロ・フラクトグラフィー的に特定することを試みた。そ
の結果、図２および図３において○印の部位が破壊の起
点であることが特定できた。なお、図４は図２の破壊起
点における金属組織を表す１０００倍の顕微鏡写真であ
り、図５は図３の破壊起点における金属組織を表す１０
００倍の顕微鏡写真であって、いずれも疲労破壊である
ことが明らかである。Although it is not easy to identify the primary damage site from these fracture surfaces, the present inventors tried to identify it by macro and micro fractography. As a result, it was possible to identify that the part marked with a circle in FIG. 2 and FIG. 3 was the starting point of the fracture. Note that FIG. 4 is a 1000 × micrograph showing the metal structure at the fracture starting point of FIG. 2, and FIG. 5 shows the metal structure at the fracture starting point of FIG.
It is a micrograph of 00 times, and it is clear that all of them are fatigue fractures.
【００１８】図２に示したように従来例１は歯すじ方向
中央部から疲労破壊が始まっているのに対して、図３に
示したように従来例２は大端エッジ部より疲労破壊が始
まっている。従来例１も従来例２も共にラッピング工程
において歯当たりを歯すじ方向中央部になるように調整
しており、単なる歯当たりの違いで破損状態の差異が生
じたものではない。そこで、本発明者等はトルク入力時
の歯当たり移動という観点から次の仮説を立てた。As shown in FIG. 2, in the conventional example 1, the fatigue fracture starts from the central portion in the tooth trace direction, whereas in the conventional example 2, the fatigue fracture starts from the large edge portion as shown in FIG. It has begun. In both the conventional example 1 and the conventional example 2, the tooth contact is adjusted so as to be located at the central portion in the tooth trace direction in the lapping process, and the difference in the damage state does not occur due to the mere difference in the tooth contact. Therefore, the present inventors made the following hypothesis from the viewpoint of tooth contact movement when torque is input.
【００１９】ハイポイドギヤ対は入力トルクを増すに従
って、ベアリング支持部、ギヤ類を取り付けるケース類
にたわみが生じてゆくことで、徐々に大端歯先部に歯当
たりが移動してゆくが、その移動量は従来例２の方が従
来例１より大きくなり、上記破損状態の差異を生じさせ
た。また、そのトルク入力に対する歯当たり移動量の差
は、次のようなことに起因していると考えた。As the input torque of the hypoid gear pair increases, the bearing support portion and the case to which the gears are attached are flexed, so that the tooth contact gradually moves to the tooth tip of the large end. The amount of the conventional example 2 was larger than that of the conventional example 1, and the above-mentioned difference in the damaged state was caused. The difference in the tooth contact movement amount with respect to the torque input was considered to be due to the following factors.
【００２０】従来例１と従来例２では歯形には全く差異
がないため、トルク入力に対して同じように大端歯先に
移動してゆくが、従来例１は最表面に浸炭異常層という
Ｈｖ４００〜５００程度の軟質層が存在するため、潰れ
が生じ面当たりになるのに対して、従来例２は浸炭異常
層を化学研磨によって完全に除去したので、上記クッシ
ョン作用は生じず大端歯先に局部当たりとなってしま
い、実質の歯当たり移動量が大きくなったものと考え
た。Since there is no difference in tooth profile between Conventional Example 1 and Conventional Example 2, they move to the tooth end at the large end in the same manner in response to torque input, but Conventional Example 1 has an abnormal carburized layer on the outermost surface. Since there is a soft layer having a Hv of about 400 to 500, the surface is crushed and comes into contact with the surface. On the other hand, in Conventional Example 2, the abnormal carburizing layer is completely removed by chemical polishing, so that the cushioning action does not occur and the large end tooth It was thought that the tooth contact had already occurred locally, and the actual amount of tooth contact movement increased.
【００２１】そこで、発明者等は前記の歯当たり移動量
を制御してヒール当たりから正しい当たりに近づけれ
ば、浸炭異常層のない疲労強度に優れた部位での面当た
りを可能とし、疲労強度の向上を図れるものと考え、歯
当たり移動量を制御できる方策について鋭意検討を重ね
た。その結果、ハイポイドギヤ対に適当なエンドレム加
工を施すことを着想し、実際に試作、評価を重ねるうち
に本発明に到ったものである。[0021] Therefore, the inventors of the present invention, by controlling the above-mentioned amount of tooth contact movement to bring it closer to the correct contact from the heel contact, it is possible to achieve surface contact at a portion having excellent carburizing fatigue strength and excellent fatigue strength. We thought that it would be possible to improve the tooth movement, and conducted intensive studies on measures to control the amount of tooth contact movement. As a result, the inventors arrived at the present invention while actually trial-producing and evaluating the idea of performing an appropriate endrem processing on the hypoid gear pair.
【００２２】本発明の高強度ハイポイド歯車は、ハイポ
イド歯車対のドライブピニオンまたはリングギヤのいず
れか一方または両方の歯部大端にエンドレム加工を施
し、歯部に浸炭焼入れした後、ショットピーニング処理
し、さらに化学研磨を施したことを要旨とする。The high-strength hypoid gear of the present invention has end teeth processing on the tooth ends of one or both of the drive pinion and the ring gear of the hypoid gear pair, and after carburizing and quenching the teeth, shot peening treatment is performed. The point is that chemical polishing is further performed.
【００２３】歯部大端に施すエンドレム加工は、ハイポ
イド歯車対のドライブピニオンまたはリングギヤのいず
れか一方でも良く、あるいは両方であっても良い。要は
ドライブピニオンとリングギヤの歯当たり移動量が適正
に制御できれば良い。The endrem processing applied to the large end of the tooth portion may be performed on either one of the drive pinion or the ring gear of the hypoid gear pair, or both. The point is that the amount of tooth contact movement of the drive pinion and the ring gear should be properly controlled.
【００２４】エンドレム量については、例えばリングギ
ヤにのみ施す場合、図１に示したように、エンドレム１
０の長さＬは大端１２から小端１４までの距離の１／１
５〜１／４、高さｘは０．０２〜０．３ｍｍとすること
が好ましい。エンドレムの長さＬが１／１５未満では歯
当たり移動量の抑制効果が充分でなく、良好な強度特性
が得られず、また１／４を越えると実質の噛み合い率の
低下により振動、騒音レベルが急激に高くなるため、大
端から小端までの距離の１／１５〜１／４に限定した。
エンドレムの高さｘについては、０．０２ｍｍ未満では
歯当たり移動量の抑制効果が充分でなく、良好な強度特
性が得られず、また０．３ｍｍを越えるとエッヂ効果が
急激に顕著になるため、ピッチングの発生が著しくなる
ので、０．０２〜０．３ｍｍに限定した。Regarding the amount of end rem, for example, when it is applied only to the ring gear, as shown in FIG.
The length L of 0 is 1/1 of the distance from the large end 12 to the small end 14.
It is preferable that the height is 5 to 1/4 and the height x is 0.02 to 0.3 mm. If the length L of the end rem is less than 1/15, the effect of suppressing the amount of tooth contact movement is not sufficient, and good strength characteristics cannot be obtained. If it exceeds 1/4, the actual meshing ratio decreases and vibration and noise levels are reduced. Since it rapidly increases, the distance is limited to 1/15 to 1/4 of the distance from the large end to the small end.
Regarding the endrem height x, if it is less than 0.02 mm, the effect of suppressing the amount of tooth contact movement is not sufficient, and good strength characteristics cannot be obtained, and if it exceeds 0.3 mm, the edge effect rapidly becomes remarkable. Since pitching occurs remarkably, the pitch is limited to 0.02 to 0.3 mm.
【００２５】浸炭焼入れはＣｒ鋼、Ｃｒ−Ｍｏ鋼または
Ｎｉ−Ｃｒ−Ｍｏ鋼等の肌焼鋼を用い、固体浸炭剤等に
接触させて加熱する固体浸炭法、浸炭性雰囲気ガス中で
加熱するガス浸炭法、あるいは浸炭性塩浴に浸漬する液
体浸炭法等特に限定はない。For the carburizing and quenching, a case-hardening steel such as Cr steel, Cr-Mo steel or Ni-Cr-Mo steel is used, and a solid carburizing method of contacting with a solid carburizing agent to heat it, or heating in a carburizing atmosphere gas There is no particular limitation such as a gas carburizing method or a liquid carburizing method of immersing in a carburizing salt bath.
【００２６】ショットピーニングを行う装置は従来のも
のを用いることができる。ショットの投射装置として
は、回転する翼車の羽によって加速する遠心式投射装
置、あるいは圧縮空気がノズルから噴射するときの空気
速度を利用する空気式吹付投射装置のいずれをも使用す
ることができる。A conventional device can be used for the shot peening. As the shot projection device, either a centrifugal projection device that is accelerated by the wing of a rotating impeller or a pneumatic spray projection device that uses the air velocity when compressed air is jetted from a nozzle can be used. ..
【００２７】ショット材質としては、大きなピーニング
効果を得るためには、鋼のような比較的大きな密度を有
するものが好ましい。ショット材質が鋼の場合には、通
常ビッカース硬さ（Ｈｖ）で４５０〜６００程度のもの
でも良いが、疲労強度効果を高めるためには６００〜８
００程度のものの方が好ましい。As the shot material, in order to obtain a large peening effect, one having a relatively large density such as steel is preferable. When the shot material is steel, it may have a Vickers hardness (Hv) of approximately 450 to 600, but it is 600 to 8 in order to enhance the fatigue strength effect.
It is preferably about 00.
【００２８】ショットピーニングを施すときの強さは、
アークハイトで表すと０．１ｍｍ以上とするのが良い。
アークハイトが０．１ｍｍ未満ではピーニング効果を得
ることが困難となる。また、カバレージは、ショット投
射面全体にピーニング効果を付与できるよう１００％以
上とすることが好ましい。投射粒子の速度は、３０〜７
０ｍ／ｓｅｃで０．５〜１０分程度のショット時間が好
ましい。The strength of shot peening is
When expressed in terms of arc height, it is good to set it to 0.1 mm or more.
If the arc height is less than 0.1 mm, it becomes difficult to obtain the peening effect. Further, the coverage is preferably 100% or more so that the peening effect can be given to the entire shot projection surface. The speed of projection particles is 30 to 7
A shot time of 0.5 to 10 minutes at 0 m / sec is preferable.
【００２９】化学研磨処理工程において用いる化学研磨
液は、酸＋酸化剤とから構成される一般のものを使用で
きるが、本発明では、特に、酸としてフッ酸を、酸化剤
として過酸化水素を用いたものであることが好ましい。
フッ酸は通常の酸としての働きにより、鋼材表面を化学
的に除去する。また、過酸化水素はその強い酸化力に加
え、鉄イオンを錯体として固定するため、過酸化水素の
分解作用を抑制し、長時間の安定的な処理を可能とす
る。The chemical polishing liquid used in the chemical polishing treatment step may be a general one composed of an acid and an oxidizing agent. In the present invention, hydrofluoric acid is used as the acid and hydrogen peroxide is used as the oxidizing agent. The one used is preferable.
The hydrofluoric acid acts as a normal acid to chemically remove the steel surface. Further, hydrogen peroxide, in addition to its strong oxidizing power, fixes iron ions as a complex, thus suppressing the decomposition action of hydrogen peroxide and enabling stable treatment for a long time.
【００３０】[0030]
【作用】本発明の高強度ハイポイド歯車は、ハイポイド
歯車対のドライブピニオンまたはリングギヤのいずれか
一方または両方の歯部大端にエンドレム加工を施したの
で、トルク入力時の歯当たり移動量を制御してヒールで
の局部当たりから適正なる歯当たりに近づけることがで
きる。また、歯部の浸炭焼入れ処理およびショットピー
ニング処理後に浸炭異常層等の表面欠陥層を除去したの
で、疲労強度に優れた部位での面当たりを可能とし、疲
労強度が著しく向上した。In the high-strength hypoid gear of the present invention, the tooth contact movement amount at the time of torque input is controlled because the toothed ends of one or both of the drive pinion and the ring gear of the hypoid gear pair are subjected to the endrem processing. It is possible to get close to a proper tooth contact from the local contact at the heel. Further, the surface defect layer such as the abnormal carburizing layer was removed after the carburizing and quenching treatment and the shot peening treatment of the tooth portion, so that it was possible to make the surface contact with the portion having excellent fatigue strength, and the fatigue strength was remarkably improved.
【００３１】[0031]
【実施例】本発明の実施例を従来例と比較しつつ説明
し、本発明の効果を明らかにする。本発明例としてＪＩ
Ｓ ＳＣＭ４２０鋼素材から熱間鍛造にてハイポイドギ
ヤ対の粗形材を製作し、ブランク加工後ヘリックスフォ
ームにて歯切り加工を行った。その際に図１に示すエン
ドレムの長さＬ＝６ｍｍ、エンドレムの高さｘ＝０．１
ｍｍの大端エンドレムをつけるため、リードカムを通常
のものから変更して加工を行った。なお、ハイポイドギ
ヤ対の主な諸元は表１に示す通りである。EXAMPLES Examples of the present invention will be described in comparison with a conventional example to clarify the effects of the present invention. As an example of the present invention, JI
A rough shaped material of a hypoid gear pair was manufactured from S SCM420 steel material by hot forging, and gear cutting was performed with a helix form after blank processing. At that time, the length L of the end rem shown in FIG. 1 is 6 mm and the height of the end rem x is 0.1.
In order to attach a large end rem of mm, the lead cam was changed from a normal one and processed. The main specifications of the hypoid gear pair are as shown in Table 1.
【００３２】[0032]
【表１】 [Table 1]
【００３３】その後有効硬化深さ１．０ｍｍ、表面炭素
濃度０．８％を狙って浸炭焼入れを施し、平均粒径０．
８ｍｍ、硬度Ｈｖ７００のショット粒で投射速度５０ｍ
／ｓｅｃにて、カバレージ６００％のショットピーニン
グを施した。その時のアークハイト値は０．６７ｍｍで
あった。After that, carburizing and quenching were performed aiming at an effective hardening depth of 1.0 mm and a surface carbon concentration of 0.8%, and an average grain size of 0.
Projection speed of 50m with shot particles of 8mm and hardness Hv700
/ Sec, shot peening with a coverage of 600% was performed. The arc height value at that time was 0.67 mm.
【００３４】次に、ＨＦ−Ｈ2Ｏ2系化学系研磨液に３分
間浸漬して浸炭異常層を完全に除去し、表面を鏡面化さ
せた。その時の面粗度を歯面において測定したところＲ
ｚ〜１．５μｍであった。そして、ギヤ・キットのラッ
ピング、組み付け工程を経てユニット状態での疲労評価
に供した。なお、比較のために本実施例と同様の大端部
にエンドレム加工を施し、浸炭焼入れおよびショットピ
ーニング後の化学研磨を省略した比較例についても、同
一条件で破損に至るまでの繰り返し数を測定した。得ら
れた結果は、エンドレム加工を施さなかった従来例１お
よび従来例２と共に表２にまとめて示した。Next, the carburized abnormal layer was completely removed by immersing it in a HF-H 2 O 2 -based chemical polishing liquid for 3 minutes to make the surface mirror-finished. When the surface roughness at that time was measured on the tooth surface, R
It was z-1.5 micrometers. Then, after undergoing the wrapping and assembling steps of the gear kit, the fatigue evaluation in the unit state was performed. For comparison, in the comparative example in which end lam processing was applied to the same large end as in this example, and chemical polishing after carburizing and shot peening was omitted, the number of repetitions until failure was measured under the same conditions. did. The obtained results are collectively shown in Table 2 together with the conventional example 1 and the conventional example 2 which were not subjected to the endrem processing.
【００３５】[0035]
【表２】 [Table 2]
【００３６】表２から明らかなように、大端部にエンド
レム加工および化学研磨の無かった従来例１は７９万回
であるのに、これに化学研磨を施した従来例２は歯当た
り移動量が多くヒールでの局部当たりのため、寿命が５
０万回と却って疲労強度に劣ったことは前記の通りであ
るが、大端部にエンドレム加工を施し化学研磨の無かっ
た比較例は、歯幅が細くなったため、寿命は５５万回で
あって、寿命の向上は見られなかった。これに対して、
本実施例はエンドレム加工によって、歯当たり移動量の
制御により、寿命が１６１万回であって、本発明により
疲労強度が大幅に向上することが確認された。As is clear from Table 2, the conventional example 1 in which the endless processing and the chemical polishing were not performed on the large end was 790,000 times, while the conventional example 2 in which the chemical polishing was performed on this was a tooth contact movement amount. There is a lot of local contact at the heel, so life is 5
As described above, the fatigue strength was inferior even if it was 0,000 times. However, the comparative example in which the end end was processed at the large end and there was no chemical polishing had a narrow tooth width, so the life was 550,000 times. Therefore, the life was not improved. On the contrary,
In this example, it was confirmed that the life was 16.10 million times by controlling the tooth contact movement amount by the endrem processing, and the fatigue strength was significantly improved by the present invention.
【００３７】[0037]
【発明の効果】本発明の高強度ハイポイド歯車は以上詳
述したように、ハイポイド歯車対のドライブピニオンま
たはリングギヤのいずれか一方または両方の歯部大端に
エンドレム加工を施し、歯部に浸炭焼入れした後ショッ
トピーニング処理をし、さらに化学研磨を施したことを
特徴とするものであって、大端部のエンドレムによりト
ルク入力時の歯当たり移動量が制御されヒールでの局部
当たりから適正位置での歯当たりに近づけることができ
る。また、歯部の浸炭焼入れ処理およびショットピーニ
ング処理後に化学研磨により浸炭異常層等の表面欠陥層
を除去したので、ドライブピニオンとリングギヤとの歯
当たりが疲労強度に優れた部位での面当たりとなり、疲
労強度を著しく向上することができる。As described above in detail, the high-strength hypoid gear of the present invention has end teeth processing applied to the tooth ends of either or both of the drive pinion and the ring gear of the hypoid gear pair, and the teeth are carburized and quenched. After that, shot peening is performed and chemical polishing is further applied.The end rem of the large end controls the amount of tooth contact movement at the time of torque input, and from the local contact at the heel to the proper position. You can get close to the tooth contact. Further, since the surface defect layer such as the abnormal carburizing layer is removed by chemical polishing after the carburizing and quenching treatment and the shot peening treatment of the tooth portion, the tooth contact between the drive pinion and the ring gear becomes a surface contact at a portion excellent in fatigue strength, Fatigue strength can be significantly improved.
【図１】大端部にエンドレム加工したリングキヤの歯部
の部分斜視図である。FIG. 1 is a partial perspective view of a tooth portion of a ring carrier having a large end portion endremed.
【図２】化学研磨をしなかった従来例のリングギヤの破
損部位の模写図である。FIG. 2 is a copy drawing of a damaged portion of a conventional ring gear that has not been chemically polished.
【図３】化学研磨を施した従来例のリングギヤの破損部
位の模写図である。FIG. 3 is a copy of a damaged portion of a conventional ring gear that has been chemically polished.
【図４】図２の従来例の破損起点部の金属組織を表す１
０００倍の顕微鏡写真である。FIG. 4 is a diagram 1 showing the metallographic structure of the damage starting point of the conventional example of FIG.
It is a microscope photograph of 000 times.
【図５】図３の従来例の破損起点部の金属組織を表す１
０００倍の顕微鏡写真である。FIG. 5 shows a metallographic structure of a starting point of damage of the conventional example of FIG.
It is a microscope photograph of 000 times.
１０ エンドレム １２ 大端 １４ 小端 10 Endrem 12 Large end 14 Small end
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大西 昌澄 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 鈴木 康行 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 鈴木 憲一 愛知県愛知郡長久手町大字長湫字横道41番 地の１ 株式会社豊田中央研究所内 (72)発明者 梶野 正樹 愛知県愛知郡長久手町大字長湫字横道41番 地の１ 株式会社豊田中央研究所内 (72)発明者 清水 富美男 愛知県愛知郡長久手町大字長湫字横道41番 地の１ 株式会社豊田中央研究所内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masasumi Onishi 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Yasuyuki Suzuki 1, Toyota Town, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Kenichi Suzuki, 41, Nagachote, Nagachite-cho, Aichi-gun, Aichi Prefecture, 1st in Yokota Central Research Institute Co., Ltd. Toyota Central Research Institute Co., Ltd. (72) Inventor Fumio Shimizu 1 of 41, Yokomichi Nagakute-cho, Aichi-gun, Aichi Prefecture Toyota Central Research Institute
Claims (1)
たはリングギヤのいずれか一方または両方の歯部大端に
エンドレム加工を施し、歯部に浸炭焼入れした後、ショ
ットピーニング処理し、さらに化学研磨を施したことを
特徴とする高強度ハイポイド歯車。1. A drive pinion of a pair of hypoid gears or a ring gear, one or both of which has a tooth end having a large end portion subjected to endrem processing, the tooth portion being carburized and quenched, then shot peened, and chemically polished. High-strength hypoid gear characterized by.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35589291A JPH05169324A (en) | 1991-12-20 | 1991-12-20 | High strength hypoid gear |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35589291A JPH05169324A (en) | 1991-12-20 | 1991-12-20 | High strength hypoid gear |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05169324A true JPH05169324A (en) | 1993-07-09 |
Family
ID=18446266
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35589291A Pending JPH05169324A (en) | 1991-12-20 | 1991-12-20 | High strength hypoid gear |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05169324A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002009903A1 (en) * | 2000-08-01 | 2002-02-07 | Aisin Aw Co., Ltd. | Gear, and method and device for finishing tooth face of gear |
| CN111015137A (en) * | 2019-12-30 | 2020-04-17 | 江西江铃集团车桥齿轮有限责任公司 | Method for improving NVH (noise, vibration and harshness) performance of extended epicycloid hypoid gear |
-
1991
- 1991-12-20 JP JP35589291A patent/JPH05169324A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002009903A1 (en) * | 2000-08-01 | 2002-02-07 | Aisin Aw Co., Ltd. | Gear, and method and device for finishing tooth face of gear |
| CN111015137A (en) * | 2019-12-30 | 2020-04-17 | 江西江铃集团车桥齿轮有限责任公司 | Method for improving NVH (noise, vibration and harshness) performance of extended epicycloid hypoid gear |
| CN111015137B (en) * | 2019-12-30 | 2021-07-23 | 江西江铃集团车桥齿轮有限责任公司 | Method for improving NVH (noise, vibration and harshness) performance of extended epicycloid hypoid gear |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8062094B2 (en) | Process of durability improvement of gear tooth flank surface | |
| JPH02138554A (en) | Highly strenghtened gear | |
| JP2002039328A (en) | Method for enhancing fatigue strength of gear | |
| JP4441371B2 (en) | Gear with excellent fatigue characteristics and method for improving the fatigue characteristics thereof | |
| WO2007023936A1 (en) | Method of shot peening | |
| JP2005264331A (en) | Machine structural components | |
| JPH05169324A (en) | High strength hypoid gear | |
| JPS62200071A (en) | Manufacture of high-strength gear | |
| JPH10202435A (en) | Manufacture of helical gear | |
| JP3271659B2 (en) | High strength gear and manufacturing method thereof | |
| JPH06246548A (en) | Manufacture of high contact-fatigue strength gear | |
| JPH01264727A (en) | Manufacture of high strength gear | |
| JPH11230312A (en) | High contact fatigue lifetime gear and manufacture thereof | |
| JPS61117014A (en) | Manufacturing method of highly strengthened gear | |
| JPH06145785A (en) | Hot peening method for carburized steel | |
| JP2002126993A (en) | Manufacturing method for gear and its machining device | |
| JPH0754050A (en) | High strength gear excellent in root of tooth bending fatigue strength and tooth surface pitching resistance and manufacture therefor | |
| JPH11207522A (en) | Manufacture of high fatigue strength gear | |
| JP2003183808A (en) | Mechanical structural part | |
| JPS62253723A (en) | Production of gear | |
| JPH07290363A (en) | Manufacture of high-performance gear | |
| JPH08174340A (en) | Part for machine structure having excellent surface fatigue strength and manufacture thereof | |
| JPH10158743A (en) | Surface hardening treatment and gear | |
| JPH04269166A (en) | Reinforcing method for cemented part | |
| JP2006009877A (en) | Gear |