JP2016090028A - Tripod-type constant velocity universal joint and manufacturing method of tripod member of tripod-type constant velocity universal joint - Google Patents
Tripod-type constant velocity universal joint and manufacturing method of tripod member of tripod-type constant velocity universal joint Download PDFInfo
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- JP2016090028A JP2016090028A JP2014228964A JP2014228964A JP2016090028A JP 2016090028 A JP2016090028 A JP 2016090028A JP 2014228964 A JP2014228964 A JP 2014228964A JP 2014228964 A JP2014228964 A JP 2014228964A JP 2016090028 A JP2016090028 A JP 2016090028A
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- velocity universal
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
- F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
- F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
- F16D3/202—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints
- F16D3/205—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part
- F16D3/2055—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part having three pins, i.e. true tripod joints
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
- B21K1/00—Making machine elements
- B21K1/14—Making machine elements fittings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
- F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
- F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
- F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
- F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
- F16D3/202—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints
- F16D3/205—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
- F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
- F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
- F16D3/202—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints
- F16D2003/2026—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints with trunnion rings, i.e. with tripod joints having rollers supported by a ring on the trunnion
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Forging (AREA)
- Heat Treatment Of Articles (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
Abstract
Description
本発明は、自動車や産業機械等における動力伝達に使用される摺動式のトリポード型等速自在継手およびそのトリポード部材の製造方法に関する。 The present invention relates to a sliding tripod type constant velocity universal joint used for power transmission in automobiles, industrial machines, and the like, and a method for manufacturing the tripod member.
自動車や各種産業機械の動力伝達系を構成する等速自在継手は、駆動側と従動側の二軸をトルク伝達可能に連結すると共に、前記二軸が作動角をとっても等速で回転トルクを伝達することができる。等速自在継手は、角度変位のみを許容する固定式等速自在継手と、角度変位および軸方向変位の両方を許容する摺動式等速自在継手とに大別され、例えば、自動車のエンジンから駆動車輪に動力を伝達するドライブシャフトにおいては、デフ側(インボード側)に摺動式等速自在継手が使用され、駆動車輪側(アウトボード側)には固定式等速自在継手が使用される。 The constant velocity universal joint that constitutes the power transmission system of automobiles and various industrial machines connects the two shafts on the drive side and the driven side so that torque can be transmitted, and transmits rotational torque at a constant speed even if the two shafts have an operating angle. can do. Constant velocity universal joints are broadly classified into fixed constant velocity universal joints that allow only angular displacement and sliding constant velocity universal joints that allow both angular displacement and axial displacement. In the drive shaft that transmits power to the drive wheel, a sliding type constant velocity universal joint is used on the differential side (inboard side), and a fixed type constant velocity universal joint is used on the drive wheel side (outboard side). The
摺動式等速自在継手の一つとしてトリポード型等速自在継手がある。このトリポード型等速自在継手は、トルク伝達部材であるローラがシングルローラタイプと、ダブルローラタイプが知られている。図23〜図26に、ダブルローラタイプのトリポード型等速自在継手を例示する(例えば、特許文献1参照)。 One of the sliding constant velocity universal joints is a tripod type constant velocity universal joint. As for this tripod type constant velocity universal joint, the roller which is a torque transmission member is known as a single roller type and a double roller type. 23 to 26 illustrate a double roller type tripod type constant velocity universal joint (see, for example, Patent Document 1).
図23はトリポード型等速自在継手の部分縦断面図であり、図24は図23のK−K線で矢視した部分横断面図である。図23および図24に示すように、このトリポード型等速自在継手101は、外側継手部材102と、内側継手部材としてのトリポード部材103と、トルク伝達部材としてのローラユニット104とで主要部が構成されている。外側継手部材102は、一端が開口したカップ状をなし、内周面に軸方向に延びる3本の直線状トラック溝105が周方向等間隔に形成され、各トラック溝105の両側には、円周方向に対向して配置され、それぞれ軸方向に延びるローラ案内面106が形成されている。外側継手部材102の内部には、トリポード部材103とローラユニット104が収容されている。トリポード部材103は、半径方向に突出した3本の脚軸107を有する。トリポード部材103の中心孔108に形成された雌スプライン123にシャフト109に形成された雄スプライン124が嵌合し、止め輪110により軸方向に固定されている。ローラユニット104は、ローラであるアウタリング111と、このアウタリング111の内側に配置されて脚軸107に外嵌されたインナリング112と、アウタリング111とインナリング112との間に介在された多数の針状ころ113とで主要部が構成されており、外側継手部材102のトラック溝105に収容されている。インナリング112の内周面112aは、インナリング112の軸線を含む縦断面において円弧状凸面をなす。インナリング112、針状ころ113およびアウタリング111からなるローラユニット104は、ワッシャ114、115により分離しない構造となっている。 FIG. 23 is a partial longitudinal sectional view of a tripod type constant velocity universal joint, and FIG. 24 is a partial transverse sectional view taken along the line KK of FIG. As shown in FIGS. 23 and 24, the tripod type constant velocity universal joint 101 is composed mainly of an outer joint member 102, a tripod member 103 as an inner joint member, and a roller unit 104 as a torque transmission member. Has been. The outer joint member 102 has a cup shape with one end opened, and three linear track grooves 105 extending in the axial direction on the inner peripheral surface are formed at equal intervals in the circumferential direction. Roller guide surfaces 106 are formed so as to face each other in the circumferential direction and extend in the axial direction. Inside the outer joint member 102, a tripod member 103 and a roller unit 104 are accommodated. The tripod member 103 has three leg shafts 107 protruding in the radial direction. A male spline 124 formed on the shaft 109 is fitted into a female spline 123 formed in the center hole 108 of the tripod member 103, and is fixed in the axial direction by a retaining ring 110. The roller unit 104 includes an outer ring 111 that is a roller, an inner ring 112 that is disposed inside the outer ring 111 and is externally fitted to the leg shaft 107, and is interposed between the outer ring 111 and the inner ring 112. The main part is composed of a large number of needle rollers 113 and is accommodated in the track groove 105 of the outer joint member 102. The inner peripheral surface 112 a of the inner ring 112 forms an arcuate convex surface in a longitudinal section including the axis of the inner ring 112. The roller unit 104 including the inner ring 112, the needle rollers 113, and the outer ring 111 has a structure that is not separated by the washers 114 and 115.
トリポード部材103の各脚軸107の外周面は、脚軸107の軸線を含んだ縦断面においてストレート形状をなす。また、図23のL−L線で矢視した平面図である図25に示すように、脚軸107の外周面は、脚軸107の軸線に直交する横断面において略楕円形状をなし、継手の軸線と直交する方向、すなわち長軸aの方向でインナリング112の内周面112aと接触し、継手の軸線方向、すなわち短軸bの方向でインナリング112の内周面112aとの間に隙間mが形成されている。図23、図24を参照して、この等速自在継手101では、トリポード部材103の脚軸107に装着されたローラユニット104のアウタリング111が、外側継手部材102のトラック溝105のローラ案内面106上を転動する。脚軸107の横断面が略楕円形状であるので、等速自在継手101が作動角を取ったとき、外側継手部材102の軸線に対してトリポード部材103の軸線は傾斜するが、ローラユニット104はトリポード部材103の脚軸107の軸線に対して傾斜可能である。したがって、ローラユニット104のアウタリング111とローラ案内面106とが斜交した状態になることを回避し、正しく転動するので、誘起スラストやスライド抵抗の低減を図ることができ、継手の低振動化を実現することができる。 The outer peripheral surface of each leg shaft 107 of the tripod member 103 has a straight shape in a longitudinal section including the axis of the leg shaft 107. Further, as shown in FIG. 25, which is a plan view taken along the line LL in FIG. 23, the outer peripheral surface of the leg shaft 107 has a substantially elliptical shape in a cross section orthogonal to the axis of the leg shaft 107. In contact with the inner peripheral surface 112a of the inner ring 112 in the direction perpendicular to the axis of the inner ring 112, that is, in the direction of the major axis a, and between the inner peripheral surface 112a of the inner ring 112 in the direction of the axis of the joint, that is, the minor axis b. A gap m is formed. 23 and 24, in this constant velocity universal joint 101, the outer ring 111 of the roller unit 104 attached to the leg shaft 107 of the tripod member 103 is connected to the roller guide surface of the track groove 105 of the outer joint member 102. Roll over 106. Since the cross section of the leg shaft 107 is substantially elliptical, when the constant velocity universal joint 101 takes an operating angle, the axis of the tripod member 103 is inclined with respect to the axis of the outer joint member 102, but the roller unit 104 is The tripod member 103 can be inclined with respect to the axis of the leg shaft 107. Therefore, since the outer ring 111 of the roller unit 104 and the roller guide surface 106 are prevented from being in an oblique state and rolls correctly, induced thrust and slide resistance can be reduced, and the vibration of the joint can be reduced. Can be realized.
図27に示すように、トリポード部材103の製作工程として、従来、バー材切断工程S1、球状化焼なまし工程S2’、ボンデ処理工程S3、冷間鍛造工程S4、旋削加工工程S5、ブローチ加工工程S6、熱処理工程S7、研削加工工程S8を経て製作されることが特許文献2に記載されている。 As shown in FIG. 27, as a manufacturing process of the tripod member 103, conventionally, a bar material cutting process S1, a spheroidizing annealing process S2 ′, a bonding process S3, a cold forging process S4, a turning process S5, a broaching process. It is described in Patent Document 2 that it is manufactured through step S6, heat treatment step S7, and grinding step S8.
トリポード部材103は、強度や耐摩耗性及び耐はく離性を要求されることから、上記の製作工程のように浸炭焼入れ焼戻しなどの熱処理を施して硬度を高めるようにしている。ところが、図26(a)、図26(b)に示すように、トリポード部材103は、ボス部103aから脚軸107が放射状に突出した形状であるので、周方向での肉厚の変化が大きい。 Since the tripod member 103 is required to have strength, wear resistance, and peel resistance, the heat treatment such as carburizing, quenching, and tempering is performed to increase the hardness as in the above manufacturing process. However, as shown in FIGS. 26 (a) and 26 (b), the tripod member 103 has a shape in which the leg shaft 107 protrudes radially from the boss portion 103a, so that the change in the thickness in the circumferential direction is large. .
このような肉厚の変化が大きい部品を浸炭焼入れ焼戻しした場合、冷却速度が部位により異なるため熱処理変形が大きくなる。また、焼入れでの変態により膨張が生じ、この膨張は部品の体積に比例する。そのため、肉厚の厚い部位は大きく膨張し、逆に肉厚の薄い部位は小さな膨張となり、その結果、トリポード部材103の雌スプライン123のピッチ円Pは、熱処理前の真円形状から、図26(b)に示すように、肉厚の厚い脚軸形成部位Dにおいてピッチ円Pの直径が大きく、肉厚の薄い円筒状部位Cではピッチ円Pの直径が小さくなり、数十μm程度の直径差を有する略三角形状に変形する。図26(b)では、理解しやすいように雌スプライン123のピッチ円Pの直径差を誇張して図示している。 When such a part having a large change in thickness is subjected to carburizing, quenching, and tempering, the heat treatment deformation becomes large because the cooling rate differs depending on the part. In addition, expansion occurs due to transformation during quenching, and this expansion is proportional to the volume of the part. Therefore, the thick portion expands greatly, and conversely, the thin portion expands small. As a result, the pitch circle P of the female spline 123 of the tripod member 103 changes from the perfect circular shape before the heat treatment to FIG. As shown in (b), the diameter of the pitch circle P is large in the thick leg-shaft forming portion D, and the diameter of the pitch circle P is small in the thin cylindrical portion C, and the diameter is about several tens of μm. It deforms into a substantially triangular shape with a difference. In FIG. 26B, the diameter difference of the pitch circle P of the female spline 123 is exaggerated for easy understanding.
上記のような熱処理変形が生じるため、トリポード部材103の雌スプライン123にシャフト109の雄スプライン124(図23参照)を嵌合結合してトルクを伝達する場合、肉厚の薄い円筒状部位Cの雌スプライン123に大きな負荷がかかり、脚軸形成部位Dの雌スプライン123には小さな負荷となって、雌スプライン123の各歯に作用する応力が不均一になる。これにより、トリポード部材103の疲労強度の低下や疲労強度の大きなバラツキを招く場合がある。また、このようなトリポード部材103の熱処理変形によるスプライン負荷の不均一により、嵌合するシャフト109の強度を低下させる場合がある。 Since the heat treatment deformation as described above occurs, when the torque is transmitted by fitting the male spline 124 (see FIG. 23) of the shaft 109 to the female spline 123 of the tripod member 103 to transmit the torque, A large load is applied to the female spline 123, and a small load is applied to the female spline 123 at the leg shaft forming portion D, so that the stress acting on each tooth of the female spline 123 becomes uneven. Thereby, the fall of the fatigue strength of the tripod member 103 and the big variation in fatigue strength may be caused. Moreover, the strength of the shaft 109 to be fitted may be reduced due to the non-uniform spline load due to the heat treatment deformation of the tripod member 103.
このような状況にあるが、トリポード部材103の雌スプライン123の熱処理変形は、容易に、また経済的に研削仕上げすることが難しいこともあって、熱処理後仕上げ加工されずに使用されることが多い。このような事情により、トリポード部材103の材料は、モリブデン(Mo)を添加した焼入れ性がよく機械的性質に優れるクロム・モリブデン鋼(例えば、SCM420)を一般的に使用している。 Under such circumstances, the heat treatment deformation of the female spline 123 of the tripod member 103 can be easily and economically difficult to finish by grinding and may be used without finishing after heat treatment. Many. For these reasons, chromium / molybdenum steel (for example, SCM420) is generally used as the material of the tripod member 103, which is hardened with molybdenum (Mo) and has excellent mechanical properties.
ところが、クロム・モリブデン鋼は、モリブデンを添加している関係で、クロム鋼(例えば、SCr420)に比べて、材料が高価という問題がある。自動車の生産台数を考えた場合、このような材料価格問題は工業上極めて重要な問題であることに、まず着目した。 However, chromium-molybdenum steel has a problem that the material is expensive compared to chromium steel (for example, SCr420) because molybdenum is added. When considering the number of automobiles produced, we first focused on the fact that such material price problems are extremely important industrially.
熱処理変形の問題に対して、特許文献2には、トリポード部材の雌スプラインを形成する部分に対して局部的に浸炭を抑制した浸炭焼入れ焼戻しを施すことにより、雌スプラインを形成する部分を不完全焼入れ部とすると共に、当該部分を除いた表面に焼入れ部を形成し、この熱処理後に雌スプラインを形成する部分をブローチ加工する製造技術が記載されている。この製造技術は、トリポード部材の雌スプラインが真円度の高いピッチ円に形成され、かつ、歯底部の浸炭異常層が除去されることにより、高強度でかつ強度のバラツキの小さなトリポード部材を得ることができる。また、ブローチの寿命向上が図れると共に、新たな設備の導入や長い加工時間によるコストの増加や生産性の低下を抑制することができるという優れたものである。 In order to solve the problem of heat treatment deformation, Patent Document 2 discloses that the part of the tripod member where the female spline is formed is partially imperfectly formed by performing carburizing and quenching and tempering that locally suppresses carburization. A manufacturing technique is described in which a quenched portion is formed on the surface excluding the portion, and a portion where the female spline is formed after the heat treatment is broached. In this manufacturing technique, the female spline of the tripod member is formed in a pitch circle having a high roundness, and the carburized abnormal layer at the bottom of the tooth is removed, thereby obtaining a tripod member having high strength and small variation in strength. be able to. Moreover, it is possible to improve the life of the broach and to suppress an increase in cost and a decrease in productivity due to the introduction of new equipment and a long processing time.
上記のように、特許文献2は、トリポード部材に対して局部的に浸炭を抑制して浸炭焼入れ焼戻しを施すことを条件にしているが、本発明者らは、熱処理の生産性、コスト面で優れると共に、スプライン部の耐久性が良好な、ワークの全表面を浸炭焼入れ焼戻しする通常の熱処理により、真円度の高いピッチ円を有する雌スプラインの可能性の有無に着目した。 As described above, Patent Document 2 is based on the condition that carburization quenching and tempering is performed on the tripod member while locally suppressing carburization. Attention was paid to the presence or absence of a female spline having a highly round pitch circle by a normal heat treatment in which the entire surface of the workpiece was carburized, quenched, and tempered with excellent spline portion durability.
上記のような問題に鑑み、本発明は、トリポード部材を比較的安価なクロム鋼とし、全表面を浸炭焼入れ焼戻しする通常の熱処理により、加工時間の増加やコスト増加を抑制しつつ、スプラインの各歯に作用する応力を可及的に均一化し、高強度なトリポード型等速自在継手およびそのトリポード部材の製造方法を提供することを目的とする。上記の全表面を浸炭焼入れ焼戻しする処理を本明細書および特許請求の範囲において全面浸炭焼入れ焼戻しと略称する。 In view of the problems as described above, the present invention makes the tripod member a relatively inexpensive chrome steel, and suppresses an increase in processing time and an increase in cost by a normal heat treatment in which the entire surface is carburized, quenched, and tempered. An object of the present invention is to provide a high-strength tripod constant velocity universal joint and a method for manufacturing the tripod member by making stress acting on the teeth as uniform as possible. The treatment for carburizing, quenching and tempering the entire surface is abbreviated as full-surface carburizing, quenching and tempering in the present specification and claims.
本発明者らは、上記の目的を達成するために、以下に示す多面的な項目に着目し、鋭意検討および検証した結果、トリポード部材を比較的安価なクロム鋼とし、全面浸炭焼入れ焼戻しする通常の熱処理により、雌スプラインの熱処理変形を抑制するという新たなコンセプトに到達し、本発明に至った。
(1)冷間鍛造前のビレットの焼なましの評価
(2)焼なましと全面浸炭焼入れ焼戻しによるスプライン精度についての着目と検証
(3)クロム鋼からなるトリポード部材の全面浸炭焼入れ焼戻し品の実用性の検証
In order to achieve the above-mentioned object, the present inventors focused on the following multifaceted items, and as a result of intensive investigation and verification, the tripod member is made into a relatively inexpensive chrome steel, and is usually carburized and tempered entirely. Through this heat treatment, a new concept of suppressing the heat treatment deformation of the female spline has been reached, and the present invention has been achieved.
(1) Evaluation of billet annealing before cold forging (2) Attention and verification of spline accuracy by annealing and full carburizing quenching and tempering (3) Full carburizing and quenching tempered products of tripod members made of chromium steel Verification of practicality
前述の目的を達成するための技術的手段として、本発明は、円周方向の三等分位置に軸方向に延びるトラック溝を形成した外側継手部材と、ボス部の円周方向の三等分位置から半径方向に突出した脚軸を有するトリポード部材と、前記脚軸に回転自在に装着されたローラとを備え、このローラが前記トラック溝に収容され、前記ボス部の内周面にシャフトと連結するための雌スプラインが形成されたトリポード型等速自在継手において、前記トリポード部材は、クロム鋼からなり、全面浸炭焼入れ焼戻しによる硬化層が形成され、前記雌スプラインは、その小径部の真円度が20μm以下の精度の高いスプラインで形成されていることを特徴とする。 As technical means for achieving the above-mentioned object, the present invention includes an outer joint member in which a track groove extending in the axial direction is formed at a circumferential trisection position, and a circumferential trisection of the boss portion. A tripod member having a leg shaft protruding in a radial direction from a position, and a roller rotatably mounted on the leg shaft, the roller being accommodated in the track groove, and a shaft on the inner peripheral surface of the boss portion In a tripod type constant velocity universal joint in which a female spline for connection is formed, the tripod member is made of chrome steel, a hardened layer is formed by carburizing and tempering the entire surface, and the female spline is a perfect circle of its small diameter portion. It is characterized by being formed of a highly accurate spline with a degree of 20 μm or less.
また、製造方法についての本発明は、円周方向の三等分位置に軸方向に延びるトラック溝を形成した外側継手部材と、ボス部の円周方向の三等分位置から半径方向に突出した脚軸を有するトリポード部材と、前記脚軸に回転自在に装着されたローラとを備え、このローラが前記トラック溝に収容され、前記ボス部の内周面にシャフトと連結するための雌スプラインが形成されたトリポード型等速自在継手のトリポード部材の製造方法において、前記トリポード部材のビレットとしてクロム鋼からなるバー材を切断する工程と、前記ビレットを、フェライトとパーライトの整粒化された金属組織にする完全焼なましを施す工程と、その後、前記ビレットを冷間閉塞鍛造により前記トリポード部材の素形材を形成する工程と、前記素形材に旋削加工および雌スプラインのブローチ加工を施してトリポード部材を形成する工程と、その後、このトリポード部材を全面浸炭焼入れ焼戻しする工程とを備えていることを特徴とする。 Further, the present invention about the manufacturing method is such that the outer joint member in which the track groove extending in the axial direction is formed at the circumferentially divided position, and the boss portion is protruded in the radial direction from the circumferentially divided position of the boss portion. A tripod member having a leg shaft and a roller rotatably mounted on the leg shaft, the roller being accommodated in the track groove, and a female spline for connecting to the shaft on the inner peripheral surface of the boss portion In the method for manufacturing a tripod member of a formed tripod constant velocity universal joint, a step of cutting a bar material made of chrome steel as a billet of the tripod member, and the billet is composed of a ferrite and pearlite-sized metal structure Complete annealing, forming the tripod member shape by cold-closed forging of the billet, and turning the shape. And forming a tripod member subjected to broaching the female splines, then characterized by comprising a step of carburized tempered this tripod member.
上記の構成により、トリポード部材を比較的安価なクロム鋼とし、全面浸炭焼入れ焼戻しする通常の熱処理により、加工時間の増加やコスト増加を抑制しつつ、スプラインの各歯に作用する応力を可及的に均一化し、高強度なトリポード型等速自在継手およびそのトリポード部材の製造方法を実現することができる。 With the above structure, the tripod member is made of relatively inexpensive chrome steel, and the heat acting on each tooth of the spline is suppressed as much as possible while suppressing the increase in processing time and cost increase by ordinary heat treatment by carburizing and tempering the entire surface. And a high-strength tripod constant velocity universal joint and a method for manufacturing the tripod member can be realized.
上記のクロム鋼は、SCr415又はSCr420およびこれらに相当する材料であることが好ましい。SCr415又はSCr420は比較的安価な材料であり、母材硬度が低く鍛造成形性に優れている。またグローバルに調達が可能である。さらに、炭素量の少ないSCr415材はより母材硬度が低く鍛造成形性に優れている。 The chromium steel is preferably SCr415 or SCr420 and a material corresponding to these. SCr415 or SCr420 is a relatively inexpensive material and has a low base metal hardness and excellent forging formability. Global procurement is also possible. Further, the SCr415 material having a small amount of carbon has a lower base material hardness and excellent forgeability.
上記のトリポード部材の脚軸にローラユニットが装着された形式とした場合は、誘起スラストやスライド抵抗の低減を図ることができ、継手の低振動化を実現することができる。 In the case where the roller unit is mounted on the leg shaft of the tripod member, induction thrust and slide resistance can be reduced, and low vibration of the joint can be realized.
上記のトリポード部材の脚軸に複数の針状ころを介してローラが装着された形式とした場合は、構造がシンプルで、低コスト化を図ることができる。 In the case where a roller is mounted on the leg shaft of the tripod member via a plurality of needle rollers, the structure is simple and the cost can be reduced.
本発明によれば、トリポード部材を比較的安価なクロム鋼とし、全面浸炭焼入れ焼戻しする通常の熱処理により、加工時間の増加やコスト増加を抑制しつつ、スプラインの各歯に作用する応力を可及的に均一化し、高強度なトリポード型等速自在継手およびそのトリポード部材の製造方法を実現することができる。 According to the present invention, the tripod member is made of relatively inexpensive chrome steel, and the normal heat treatment in which the entire surface is carburized, quenched, and tempered can suppress the stress acting on each tooth of the spline while suppressing an increase in processing time and cost. It is possible to realize a highly uniform tripod type constant velocity universal joint and a method for manufacturing the tripod member.
以下に本発明の実施の形態を図面に基づいて説明する。 Embodiments of the present invention will be described below with reference to the drawings.
本発明の第1の実施形態に係るトリポード型等速自在継手を図1〜7に基づいて説明する。本実施形態のトリポード型等速自在継手1はダブルローラタイプのものである。図1はトリポード型等速自在継手の縦断面図であり、図2は図1のK−K線で矢視した部分横断面図である。このトリポード型等速自在継手1は、外側継手部材2と、内側継手部材としてのトリポード部材3と、トルク伝達部材としてのローラユニット4とで主要部が構成されている。外側継手部材2は、一端が開口したカップ状をなし、内周面に軸方向に延びる3本の直線状トラック溝5が周方向等間隔に形成され、各トラック溝5の両側には、円周方向に対向して配置され、それぞれ軸方向に延びるローラ案内面6が形成されている。外側継手部材2の内部には、トリポード部材3とローラユニット4が収容されている。 A tripod type constant velocity universal joint according to a first embodiment of the present invention will be described with reference to FIGS. The tripod type constant velocity universal joint 1 of this embodiment is of a double roller type. 1 is a longitudinal sectional view of a tripod constant velocity universal joint, and FIG. 2 is a partial transverse sectional view taken along the line KK of FIG. The tripod type constant velocity universal joint 1 is composed of an outer joint member 2, a tripod member 3 as an inner joint member, and a roller unit 4 as a torque transmission member. The outer joint member 2 has a cup shape with one end opened, and three linear track grooves 5 extending in the axial direction on the inner peripheral surface are formed at equal intervals in the circumferential direction. Roller guide surfaces 6 are formed so as to face each other in the circumferential direction and extend in the axial direction. Inside the outer joint member 2, a tripod member 3 and a roller unit 4 are accommodated.
トリポード部材3は、半径方向に突出した3本の脚軸7を有する。トリポード部材3の中心孔8に形成された雌スプライン23にシャフト9に形成された雄スプライン24が嵌合し、止め輪10により軸方向に固定されている。ローラユニット4は、ローラであるアウタリング11と、このアウタリング11の内側に配置されて脚軸7に外嵌されたインナリング12と、アウタリング11とインナリング12との間に介在された多数の針状ころ13とで主要部が構成されており、外側継手部材2のトラック溝5に収容されている。インナリング12の内周面12aは、インナリング12の軸線を含む縦断面において円弧状凸面をなす。インナリング12、針状ころ13およびアウタリング11からなるローラユニット4は、ワッシャ14、15により分離しない構造となっている。 The tripod member 3 has three leg shafts 7 protruding in the radial direction. A male spline 24 formed on the shaft 9 is fitted into a female spline 23 formed in the center hole 8 of the tripod member 3, and is fixed in the axial direction by a retaining ring 10. The roller unit 4 includes an outer ring 11 that is a roller, an inner ring 12 that is disposed inside the outer ring 11 and is fitted on the leg shaft 7, and is interposed between the outer ring 11 and the inner ring 12. The main part is composed of a large number of needle rollers 13 and is accommodated in the track groove 5 of the outer joint member 2. The inner peripheral surface 12 a of the inner ring 12 forms an arcuate convex surface in a longitudinal section including the axis of the inner ring 12. The roller unit 4 including the inner ring 12, the needle roller 13, and the outer ring 11 has a structure that is not separated by washers 14 and 15.
トリポード部材3の各脚軸7の外周面は、脚軸7の軸線を含んだ縦断面においてストレート形状をなす。また、図1のL−L線で矢視した平面図である図3に示すように、脚軸7の外周面は、脚軸7の軸線に直交する横断面において略楕円形状をなし、継手の軸線と直交する方向、すなわち長軸aの方向でインナリング12の内周面12aと接触し、継手の軸線方向、すなわち短軸bの方向でインナリング12の内周面12aとの間に隙間mが形成されている。 The outer peripheral surface of each leg shaft 7 of the tripod member 3 has a straight shape in a longitudinal section including the axis of the leg shaft 7. Further, as shown in FIG. 3 which is a plan view taken along line LL in FIG. 1, the outer peripheral surface of the leg shaft 7 has a substantially elliptical shape in a cross section orthogonal to the axis of the leg shaft 7. In contact with the inner circumferential surface 12a of the inner ring 12 in the direction orthogonal to the axis of the inner ring 12, that is, in the direction of the major axis a, and between the inner circumferential surface 12a of the inner ring 12 in the direction of the axis of the joint, that is, in the direction of the minor axis b. A gap m is formed.
この等速自在継手1では、トリポード部材3の脚軸7に装着されたローラユニット4のアウタリング11が、外側継手部材2のトラック溝5のローラ案内面6上を転動する(図1、図2参照)。脚軸7の横断面が略楕円形状であるので、図4に示すように、等速自在継手1が作動角を取ったとき、外側継手部材2の軸線に対してトリポード部材3の軸線は傾斜するが、ローラユニット4はトリポード部材3の脚軸7の軸線に対して傾斜可能である。したがって、ローラユニット4のアウタリング11とローラ案内面6とが斜交した状態になることを回避し、正しく転動するので、誘起スラストやスライド抵抗の低減を図ることができ、継手の低振動化を実現することができる。 In this constant velocity universal joint 1, the outer ring 11 of the roller unit 4 mounted on the leg shaft 7 of the tripod member 3 rolls on the roller guide surface 6 of the track groove 5 of the outer joint member 2 (FIG. 1). (See FIG. 2). Since the cross section of the leg shaft 7 is substantially elliptical, the axis of the tripod member 3 is inclined with respect to the axis of the outer joint member 2 when the constant velocity universal joint 1 takes an operating angle as shown in FIG. However, the roller unit 4 can be inclined with respect to the axis of the leg shaft 7 of the tripod member 3. Therefore, since the outer ring 11 of the roller unit 4 and the roller guide surface 6 are prevented from being obliquely crossed and rolls correctly, induced thrust and slide resistance can be reduced, and the vibration of the joint can be reduced. Can be realized.
トリポード部材3を図5に基づいて説明する。図5(a)は部分縦断面図であり、図5(b)は正面図である。トリポード部材3は、ボス部3aから3本の脚軸7が放射状に突出している。脚軸7の長軸aを含む7aはインナリング12の内周面12a(図3参照)と接触する表面で、熱処理後に研削加工で仕上げられている。トリポード部材3のボス部3aの中心孔8に雌スプライン23が形成され、ピッチ円Pを有する。 The tripod member 3 will be described with reference to FIG. FIG. 5A is a partial longitudinal sectional view, and FIG. 5B is a front view. The tripod member 3 has three leg shafts 7 projecting radially from the boss 3a. 7a including the long axis a of the leg shaft 7 is a surface that comes into contact with the inner peripheral surface 12a (see FIG. 3) of the inner ring 12, and is finished by grinding after heat treatment. A female spline 23 is formed in the center hole 8 of the boss 3 a of the tripod member 3 and has a pitch circle P.
本実施形態に適用されるトリポード部材3は、クロム鋼(例えば、SCr420)からなり、全面浸炭焼入れ焼戻しによる硬化層が表面全体に形成されている。雌スプライン23は、真円度の高いピッチ円Pを有し、雌スプライン23の小径部の真円度が20μm以下の精度の高いスプラインで形成されている。 The tripod member 3 applied to this embodiment consists of chromium steel (for example, SCr420), and the hardened layer by the whole surface carburizing quenching tempering is formed in the whole surface. The female spline 23 has a pitch circle P with a high roundness, and is formed of a highly accurate spline with a roundness of a small diameter portion of the female spline 23 of 20 μm or less.
雌スプライン23の小径部の真円度の測定方法および測定結果を図6、図7に基づいて説明する。図6に小径部の真円度の測定方法の概要を示す。使用した測定機は、テーラー ホブソン株式会社 製 TALYROND 265で、トリポード部材3をスピンドル(図示省略)にセットし、トリポード部材3の軸方向中央位置で測定端子30を雌スプライン23の歯先23a(小径部23aともいう)に当接させ、スピンドルを回転させて測定した。 A method for measuring the roundness of the small-diameter portion of the female spline 23 and the measurement result will be described with reference to FIGS. FIG. 6 shows an outline of a method for measuring the roundness of the small diameter portion. The measuring machine used is TALYROND 265 manufactured by Taylor Hobson Co., Ltd., the tripod member 3 is set on a spindle (not shown), and the measuring terminal 30 is added to the tooth tip 23a (small diameter) of the female spline 23 at the axial center position of the tripod member 3. The measurement was performed by rotating the spindle.
測定結果の代表例を図7に示す。図7のEが位相1、Fが位相2、Gが位相3であり、各位相が肉厚の厚い脚軸形成部位D〔図5(b)参照〕の中央に当たる。雌スプライン23の小径部23aの真円度の求め方として、測定によって得られた形状(測定形状)における各位相の最大部と測定形状に対する内接円との差を求める。この差について、位相1のものをH1、位相2のものをH2、位相3のものをH3とした。そして、これらの差の平均値X=(H1+H2+H3)/3を雌スプライン23の小径部23aの真円度とした。本明細書および特許請求の範囲において、雌スプラインの小径部の真円度とは、上記の平均値X=(H1+H2+H3)/3を意味する。本実施形態では、雌スプライン23の小径部23aの真円度(上記の平均値X)が20μm以下の精度の高いスプラインで形成されている。図7に実線で示す本実施形態のトリポード部材についての代表例では、H1=16μm、H2=20μm、H3=18μmで、小径部23aの真円度としての平均値X=18μmとなっている。 A representative example of the measurement result is shown in FIG. E in FIG. 7 is phase 1, F is phase 2, and G is phase 3, and each phase corresponds to the center of a thick leg axis formation portion D (see FIG. 5B). As a method for obtaining the roundness of the small diameter portion 23a of the female spline 23, the difference between the maximum portion of each phase in the shape (measurement shape) obtained by measurement and the inscribed circle with respect to the measurement shape is obtained. Regarding this difference, the phase 1 was H1, the phase 2 was H2, and the phase 3 was H3. The average value X = (H1 + H2 + H3) / 3 of these differences was taken as the roundness of the small diameter portion 23a of the female spline 23. In the present specification and claims, the roundness of the small-diameter portion of the female spline means the average value X = (H1 + H2 + H3) / 3. In the present embodiment, the roundness (the above average value X) of the small-diameter portion 23a of the female spline 23 is formed by a highly accurate spline having a value of 20 μm or less. In a representative example of the tripod member of the present embodiment shown by a solid line in FIG. 7, H1 = 16 μm, H2 = 20 μm, H3 = 18 μm, and the average value X = 18 μm as the roundness of the small diameter portion 23a.
これに対して、図7に破線で示す従来のクロム・モリブデン鋼(SCM420)からなり球状化焼なましを施したトリポード部材の代表例では、H1’=28μm、H2’=32μm、H3’=30μmで、小径部23aの真円度としての平均値X=30μmとなっている。 On the other hand, in a typical example of a tripod member made of conventional chromium-molybdenum steel (SCM420) shown by a broken line in FIG. 7 and subjected to spheroidizing annealing, H1 ′ = 28 μm, H2 ′ = 32 μm, H3 ′ = At 30 μm, the average value X = 30 μm as the roundness of the small diameter portion 23a.
図7には、完全焼なましを施したものと球状化焼なましを施したものの測定結果の代表例を示したが、前記の各焼なましで試料数n=10個ずつの小径部23aの真円度を比較した結果、完全焼なましを施したものは、球状化焼なましを施したものより雌スプライン23の小径部23aの真円度が35%程度向上することが判明した。 FIG. 7 shows a representative example of the measurement results of those subjected to complete annealing and those subjected to spheroidizing annealing. In each of the above-mentioned annealing, a small diameter portion having n = 10 samples. As a result of comparing the roundness of 23a, it was found that the roundness of the small-diameter portion 23a of the female spline 23 is improved by about 35% in the case of complete annealing compared to the case of spheroidizing annealing. did.
次に、トリポード部材の製造方法についての実施形態を図8〜12に基づいて説明する。製造工程の概要を図8に示す。トリポード部材3は、バー材切断工程S1、完全焼なまし工程S2、ボンデ処理工程S3、冷間鍛造工程S4、旋削加工工程S5、ブローチ加工工程S6、熱処理工程S7、研削加工工程S8を経て製作される。本実施形態の製造工程は、従来の製造工程(図27参照)を比較すると、バー材を切断したビレットの焼なまし処理が、従来は球状化焼なましであることに対して、本実施形態では完全焼なましであるところが異なる。 Next, the embodiment about the manufacturing method of a tripod member is described based on FIGS. An outline of the manufacturing process is shown in FIG. The tripod member 3 is manufactured through the bar material cutting step S1, the complete annealing step S2, the bondering step S3, the cold forging step S4, the turning step S5, the broaching step S6, the heat treatment step S7, and the grinding step S8. Is done. The manufacturing process of this embodiment is compared with the conventional manufacturing process (see FIG. 27), whereas the annealing process of the billet cut from the bar material is conventionally spheroidizing annealing. The form is different in that it is completely annealed.
各工程の概要を説明する。各工程は、代表的な例を示すものであって、必要に応じて適宜変更や追加を行うことができる。 The outline of each process will be described. Each process shows a typical example, and can be changed or added as necessary.
[バー材切断工程S1]
鍛造重量に基づいて所定長さで切断し、ビレットを製作する。
[Bar material cutting step S1]
A billet is manufactured by cutting at a predetermined length based on the forging weight.
[完全焼なまし工程S2]
冷間鍛造の際の材料流動性(変形能)の向上と浸炭焼入れ焼戻し後の結晶粒の整粒化を図るために完全焼なましを施す。詳細は後述する。
[Complete annealing step S2]
Complete annealing is performed to improve the material fluidity (deformability) during cold forging and to adjust the grain size after carburizing, quenching and tempering. Details will be described later.
[ボンデ処理工程S3]
鍛造金型の寿命向上や鍛造性を向上するために、ビレットに潤滑性を高めるボンデ処理を施す。
[Bonde treatment process S3]
In order to improve the life of the forging die and forgeability, the billet is subjected to a bondage treatment that enhances lubricity.
[冷間鍛造工程S4]
鍛造金型のキャビティ内にビレットを投入し、ビレットを塑性加工により金型に充足させる。これにより、ボス部とボス部内周面並びに脚軸が形成されたトリポード部材の冷間鍛造品が得られる。
[Cold forging process S4]
The billet is put into the cavity of the forging die, and the billet is filled into the die by plastic working. Thereby, the cold forging goods of the tripod member in which the boss | hub part, the boss | hub part inner peripheral surface, and the leg axis | shaft were formed are obtained.
[旋削加工工程S5]
冷間鍛造品から端面、内周面等を旋削加工する。
[Turning process S5]
End face, inner peripheral surface, etc. are turned from cold forging products.
[ブローチ加工工程S6]
トリポード部材の中間製品の内周面にブローチ加工してスプラインを形成する。
[Broach processing step S6]
A spline is formed by broaching the inner peripheral surface of the intermediate product of the tripod member.
[熱処理工程S7]
トリポード部材は、強度を要求されることから、浸炭焼入れ焼戻しを施して硬度を高める。本実施形態では、スプライン部を含むトリポード部材の全表面を通常の全面浸炭焼入れ焼戻しを施す。
[Heat treatment step S7]
Since the tripod member is required to have strength, the hardness is increased by carburizing, quenching and tempering. In the present embodiment, the entire surface of the tripod member including the spline portion is subjected to normal full-surface carburizing and tempering.
[研削加工工程S8]
熱処理後、トリポード部材の脚軸の外周面を研削加工で仕上げる。
[Grinding process S8]
After the heat treatment, the outer peripheral surface of the leg shaft of the tripod member is finished by grinding.
本実施形態の完全焼なまし工程S2における処理条件は、図9に示すように、ビレットをA3変態点から50℃程度高い温度範囲(例えば、890℃)で2時間保持して均熱し、その後、A1変態点から70℃程度低い温度(例えば、660℃)まで8時間かけて炉冷し、その後、空冷する。例えば、SCr420材では840〜890℃の均熱を約2時間実施し、その後、1時間に15〜30℃の降温速度で660℃まで炉冷する。完全焼なまし後の金属組織は、図10に示す写真のように、素地はフェライト、パーライトの安定した組織となる。腐食液はナイタル5%液を用いた。以降の図14、図17も腐食液は同じである。なお、上記の840〜890℃の均熱温度は、合金成分によって若干変わってくる。 As shown in FIG. 9, the processing conditions in the complete annealing step S2 of this embodiment are as follows. The billet is soaked for 2 hours in a temperature range (for example, 890 ° C.) that is about 50 ° C. higher than the A3 transformation point. The furnace is cooled for 8 hours from the A1 transformation point to a temperature lower by about 70 ° C. (for example, 660 ° C.), and then air-cooled. For example, the SCr420 material is soaked at 840 to 890 ° C. for about 2 hours, and then cooled to 660 ° C. at a temperature lowering rate of 15 to 30 ° C. per hour. The metal structure after the complete annealing has a stable structure of ferrite and pearlite as shown in the photograph shown in FIG. As the corrosive solution, a 5% solution of night was used. The corrosive liquid is the same also in FIGS. The soaking temperature of 840 to 890 ° C. varies slightly depending on the alloy components.
ここで、完全焼なましについて定義する。本明細書および特許請求の範囲において、完全焼なましとは、処理後の金属組織がフェライトとパーライトの整粒化された組織となり、処理温度がA3変態点から50℃程度高い温度に製品を均熱した後、A1変態点から70℃程度低い温度までゆっくり炉冷する焼なましを意味する。 Here, complete annealing is defined. In the present specification and claims, complete annealing means that the metal structure after processing becomes a grain-sized structure of ferrite and pearlite, and the processing temperature is about 50 ° C. higher than the A3 transformation point. After soaking, it means annealing in which the furnace is slowly cooled to a temperature about 70 ° C. lower than the A1 transformation point.
完全焼なまし後のビレットの冷間鍛造工程S4を図12に基づいて説明する。図12(b)は金型の縦断面図であり、図12(a)は、図12(b)のM−M線で矢視した横断面図である。図12(a)および図12(b)に示すように、上側ダイス40、下側ダイス41、上側パンチ42、下側パンチ43からなる金型による閉塞鍛造により、トリポード部材3の鍛造品3’が形成される。具体的には、上側ダイス40と下側ダイス41を型締めして成形空間を形成し、その中に円筒状のビレットが投入される。そして、上側パンチ42と下側パンチ43を接近させて、ビレットを加圧しダイス40、41内に充足させて、3本の脚軸7’を有する鍛造品3’が得られる。 The billet cold forging step S4 after complete annealing will be described with reference to FIG. FIG. 12B is a longitudinal sectional view of the mold, and FIG. 12A is a transverse sectional view taken along the line MM in FIG. 12B. As shown in FIGS. 12 (a) and 12 (b), the forged product 3 ′ of the tripod member 3 is formed by closed forging using a die composed of an upper die 40, a lower die 41, an upper punch 42, and a lower punch 43. Is formed. Specifically, the upper die 40 and the lower die 41 are clamped to form a molding space, and a cylindrical billet is placed therein. Then, the upper punch 42 and the lower punch 43 are brought close to each other, the billet is pressurized and filled in the dies 40 and 41, and a forged product 3 'having three leg shafts 7' is obtained.
次に、鍛造品3’は、旋削加工工程S5で端面、内周面等が旋削加工され、ブローチ加工工程S6で内周面にスプラインが形成されてトリポード部材3の中間製品となる。その後、トリポード部材3の中間製品は、熱処理工程S7で全面浸炭焼入れ焼戻しが施される。 Next, the forged product 3 ′ is turned at the end surface and the inner peripheral surface in the turning step S <b> 5, and a spline is formed on the inner peripheral surface at the broaching step S <b> 6 to become an intermediate product of the tripod member 3. Thereafter, the intermediate product of the tripod member 3 is subjected to full-surface carburizing and tempering in the heat treatment step S7.
全面浸炭焼入れ焼戻しの処理条件を次に説明する。まず、トリポード部材3の中間製品を850℃で1時間均熱保持し、その後、940℃まで加熱し、この温度で3時間浸炭・拡散し、浸炭・拡散が終了すると、炉冷して860℃になるまで温度を下げて、860℃で30分保持した後、油焼入れする。焼戻しは180℃で40分保持する条件とした。処理品のサイズ等が異なれば、適宜処理条件を変える。 Next, the processing conditions for the entire carburizing quenching and tempering will be described. First, the intermediate product of tripod member 3 is kept soaked at 850 ° C. for 1 hour, then heated to 940 ° C., carburized and diffused at this temperature for 3 hours, and when carburized and diffused, the furnace is cooled to 860 ° C. The temperature is lowered until the temperature reaches 860 ° C. for 30 minutes, followed by oil quenching. Tempering was carried out at 180 ° C. for 40 minutes. If the size of the processed product is different, the processing conditions are appropriately changed.
浸炭焼入れ焼戻し後の金属組織は、図11に示す写真のように結晶粒の成長はなく整粒化が安定している。この結晶粒の整粒化により、前述したように、本実施形態のトリポード部材3の雌スプライン23は、その小径部23aの真円度が20μmの精度の高いスプラインで形成されるものと考えられる。なお、腐食液は粒界現出液を用いた。以降の図15、図18も腐食液は同じである。 The metal structure after carburizing, quenching, and tempering has no grain growth as shown in the photograph in FIG. By adjusting the grain size, as described above, the female spline 23 of the tripod member 3 of the present embodiment is considered to be formed of a highly accurate spline with a roundness of the small diameter portion 23a of 20 μm. . In addition, the grain boundary appearing liquid was used for the corrosive liquid. The corrosive liquid is the same also in FIGS.
ここで、前述したトリポード型等速自在継手ついての第1の実施形態およびトリポード部材の製造方法についての本実施形態に至った開発経緯を説明する。総括として、トリポード部材を比較的安価なクロム鋼とすることに着目した後、以下に示す多面的な項目に着目し、鋭意検討および検証した結果、トリポード部材を比較的に安価なクロム鋼とし、表面全部を浸炭焼入れ焼戻しする通常の熱処理により、雌スプラインの熱処理変形を抑制するという新たなコンセプトに到達した。
(1)冷間鍛造前のビレットの焼なましの評価
(2)焼なましと全面浸炭焼入れ焼戻しによるスプライン精度についての着目と検証
(3)クロム鋼からなるトリポード部材の全面浸炭焼入れ焼戻し品の実用性の検証
Here, the development background which led to this embodiment about the 1st Embodiment about the tripod type constant velocity universal joint mentioned above and the manufacturing method of a tripod member is demonstrated. In summary, after focusing on making the tripod member a relatively inexpensive chrome steel, focusing on the following multifaceted items, and as a result of intensive investigation and verification, the tripod member was made a relatively cheap chrome steel, We have reached a new concept of suppressing the heat treatment deformation of female splines by the usual heat treatment of carburizing, quenching and tempering the entire surface.
(1) Evaluation of billet annealing before cold forging (2) Attention and verification of spline accuracy by annealing and full carburizing quenching and tempering (3) Full carburizing and quenching tempered products of tripod members made of chromium steel Verification of practicality
(1)冷間鍛造前のビレットの焼なましの評価
トリポード部材の製作工程として、図27に示すように、従来、クロム・モリブデン鋼製のバー材を切断してビレットを製作し、その後、ビレットを球状化焼なまし工程S2’により球状化焼なましを施している。これは、軟化しやすい球状化焼なましは、強度や耐久性が要求される転がり軸受や等速自在継手の構成部材の冷間鍛造において定常的に行われるもので、冷間鍛造の際の材料流動性(変形能)を向上させるという点で優れている。
(1) Evaluation of billet annealing before cold forging As a manufacturing process of a tripod member, as shown in FIG. 27, conventionally, a billet was manufactured by cutting a bar material made of chromium / molybdenum steel, The billet is spheroidized by the spheroidizing annealing step S2 ′. This is because spheroidizing annealing, which is easy to soften, is regularly performed in cold forging of components of rolling bearings and constant velocity universal joints that require strength and durability. It is excellent in terms of improving material fluidity (deformability).
しかしながら、機械的特性に優れるクロム・モリブデン鋼(SCM420)から特性面で厳しいクロム鋼(SCr420)に転換するためには、ビレットの焼なまし処理という原点に戻って抜本的に検討する必要があることに着目し、ビレットの焼なまし処理について評価した。 However, in order to switch from chromium-molybdenum steel (SCM420), which has excellent mechanical properties, to chromium steel (SCr420), which is severe in terms of characteristics, it is necessary to return to the origin of billet annealing treatment and study drastically. Attention was paid to the fact that billet annealing treatment was evaluated.
そこで、冷間鍛造の際の軟化目的で従来より定常的に行われている球状化焼なまし処理をクロム鋼からなるビレットに施した。球状化焼なましの処理条件は、図13に示すように、A1変態点より高い780℃で10時間均熱保持した後、660℃まで2時間かけて炉冷し、その後、空冷した。球状化焼なまし処理を施した結果、図14に示す写真のように均一に球状化が進行せず、部分的に球状化した金属組織となることが判明した。これは、炭素量の低い肌焼き鋼を球状化焼なまし処理をした場合、球状化するパーライト量が少ないために均一に球状化が進行せず、部分的な球状化となることが考えられる。 Therefore, the billet made of chromium steel was subjected to spheroidizing annealing, which has been routinely performed for the purpose of softening during cold forging. As shown in FIG. 13, the spheroidizing annealing was carried out by soaking at 780 ° C., which is higher than the A1 transformation point, for 10 hours, followed by furnace cooling to 660 ° C. over 2 hours, and then air cooling. As a result of the spheroidizing annealing treatment, it was found that spheroidization did not proceed uniformly as shown in the photograph shown in FIG. 14, and a partially spheroidized metal structure was obtained. It is considered that when spheroidizing annealing is performed on a case-hardened steel with a low carbon content, since the amount of pearlite to be spheroidized is small, spheroidization does not proceed uniformly and partial spheroidization occurs. .
上記の知見が引き金となって、クロム鋼(SCr420)のビレットの冷間鍛造前の焼なまし処理として、応力除去焼なましと完全焼なましを施して金属組織を調査した。応力除去焼なましの条件を図16に示す。すなわち、A1変態点近傍の720℃で6時間均熱保持し、その後空冷した。図17に示す写真は、応力除去焼なまし後の金属組織であり、素地はフェライト、パーライトになることが判明した。完全焼なましについては、製造方法についての本実施形態で前述したとおりである。すなわち、処理条件は図9と同じであり、完全焼なまし後の金属組織は図10に示す写真と同じで、素地はフェライト、パーライト組織である。完全焼なましの場合は、フェライト、パーライト組織がくずれにくくなっていることが判明した。 Triggered by the above knowledge, as an annealing process before cold forging of a billet of chromium steel (SCr420), the metal structure was investigated by applying stress-relieving annealing and complete annealing. FIG. 16 shows the conditions for stress relief annealing. That is, it was kept soaked at 720 ° C. near the A1 transformation point for 6 hours, and then air-cooled. The photograph shown in FIG. 17 is a metal structure after stress-relief annealing, and it has been found that the substrate is made of ferrite and pearlite. The complete annealing is as described above in the present embodiment regarding the manufacturing method. That is, the processing conditions are the same as in FIG. 9, the metal structure after complete annealing is the same as the photograph shown in FIG. 10, and the substrate is a ferrite and pearlite structure. In the case of complete annealing, it was found that the ferrite and pearlite structures are difficult to break down.
(2)焼なましと全面浸炭焼入れ焼戻しによるスプライン精度についての着目と検証
(1)項の知見が全面浸炭焼入れ焼戻しによるスプライン精度の追求への動機付けとなった。そこで、球状化焼なまし、応力除去焼なまし、完全焼なましを施した各ビレットを浸炭焼入れ焼戻しした。浸炭焼入れ焼戻しの処理条件は、製造方法についての本実施形態で前述した条件と同じである。浸炭焼入れ焼戻し後の金属組織を調査した結果、球状化焼なましを施したものは、図15に示す写真のように部分的に結晶粒が粗大化した。この検証結果から、部分的に球状化した斑な組織に浸炭焼入れ焼戻しを施すと部分的に結晶粒が急成長し粗大化することが判明した。ここで、旧オーステナイト粒径の粗大化とは、通常5〜50μm程度の大きさに揃っているが、それ以上の粒径を粗大化したものとする。
(2) Attention and verification of spline accuracy by annealing and full-surface carburizing and tempering The knowledge in (1) has motivated the pursuit of spline accuracy by full-body carburizing and tempering. Therefore, each billet subjected to spheroidizing annealing, stress-relieving annealing, and complete annealing was carburized and tempered. The conditions for carburizing, quenching and tempering are the same as those described above in the present embodiment for the manufacturing method. As a result of investigating the metal structure after carburizing and quenching and tempering, the grains subjected to spheroidizing annealing were partially coarsened as shown in the photograph in FIG. From this verification result, it was found that when carburizing, quenching and tempering was performed on a partially spheroidized uneven structure, the crystal grains partially grew and became coarse. Here, the coarsening of the prior austenite grain size is usually about 5 to 50 μm, but the grain size larger than that is coarsened.
一方、応力除去焼なましを施したものは、図18に示す写真のように結晶粒の成長はなく整粒化され、さらに、完全焼なましを施したものは、製造方法についての本実施形態で前述したとおりであった。すなわち、完全焼なましを施したものの浸炭焼入れ焼戻し後の金属組織は、図11に示す写真のように結晶粒の成長はなく整粒化が安定していることが判明した。さらに、この検証結果から、結晶粒が整粒化された金属組織は、熱処理変形の抑制、スプライン精度への好影響を与えるのではないかということに着目し、クロム鋼からなるトリポード部材の雌スプラインの小径部の真円度の検証を進める動機付けとなった。 On the other hand, those subjected to stress relief annealing are sized without crystal growth as shown in the photograph shown in FIG. 18, and those subjected to complete annealing are subjected to the present manufacturing method. The form was as described above. That is, it was found that the metal structure after carburizing, quenching, and tempering, which had been completely annealed, had no crystal grain growth as shown in FIG. Furthermore, from this verification result, focusing on the fact that the metal structure in which the crystal grains are sized has a positive effect on the deformation of the heat treatment and the spline accuracy, the female of the tripod member made of chromium steel is considered. It became a motivation to verify the roundness of the small diameter part of the spline.
雌スプラインの小径部の真円度の検証結果は、トリポード型等速自在継手についての第1の実施形態において、図7に基づいて前述したとおりであり、完全焼なましを施したものは、従来の球状化焼なましを施したものより雌スプラインの小径部の真円度が35%程度向上することが判明した。 The verification result of the roundness of the small-diameter portion of the female spline is as described above with reference to FIG. 7 in the first embodiment of the tripod type constant velocity universal joint. It has been found that the roundness of the small-diameter portion of the female spline is improved by about 35% as compared with the conventional spheroidizing annealing.
(3)クロム鋼からなるトリポード部材の全表面浸炭焼入れ焼戻し品の実用性の検証
以上の経緯を経て、クロム鋼からなるトリポード部材の全面浸炭焼入れ焼戻し品の実用性を評価した。具体的には、クロム鋼(SCr420)からなるビレットに完全焼なましを施したトリポード部材(本発明品)とクロム・モリブデン鋼(SCM420)からなるビレットに球状化焼なましを施したトリポード部材(従来品)を、それぞれ、トリポード型等速自在継手に組込んで片振り捩り疲労試験を実施した。試験結果を表1に示す。
片振り捩り疲労試験結果より、従来品の破損までの繰返し数を基準として、本発明品は、負荷条件が0〜0.6GPaおよび0〜0.7GPaの低負荷域での疲労強度が従来品と同等であることが分かった。負荷条件が0〜0.9GPaの高負荷域での疲労強度については、本発明品は従来品より若干劣る結果となったが、実用上問題がないことが確認できた。上記試験の結果、破損個所がスプラインの歯底部であり、クロム鋼(SCr420)からなるビレットに完全焼なましを施した本発明品は、破損起点となるスプライン歯底部の強度が向上することが分かった。 Based on the results of the uniaxial torsional fatigue test, the product of the present invention has a fatigue strength in a low load range of 0 to 0.6 GPa and 0 to 0.7 GPa based on the number of repetitions until the conventional product is damaged. Was found to be equivalent. Regarding the fatigue strength in a high load range of 0 to 0.9 GPa under load conditions, the product of the present invention was slightly inferior to the conventional product, but it was confirmed that there was no practical problem. As a result of the above test, the damaged part is the tooth bottom part of the spline, and the product of the present invention in which the billet made of chrome steel (SCr420) is completely annealed improves the strength of the spline tooth bottom part that becomes the starting point of the damage. I understood.
完全焼なまし後の硬度は条件にもよるが、球状化焼なまし後の硬度より若干高め(HRBスケールで5ポイント程度)となる傾向がある。しかし、ビレットの冷間鍛造において実用上問題がないことが確認できた。また、SCr415材を使用すれば、母材硬度が低くなり冷間鍛造が優れている。 The hardness after complete annealing tends to be slightly higher than the hardness after spheroidizing annealing (about 5 points on the HRB scale) depending on conditions. However, it was confirmed that there was no practical problem in cold forging of the billet. Further, if the SCr415 material is used, the base material hardness is lowered and the cold forging is excellent.
以上のような種々の検討、検証を通じて、トリポード部材を比較的に安価なクロム鋼とし、全面浸炭焼入れ焼戻しする通常の熱処理により、雌スプラインの熱処理変形を抑制するという新たなコンセプトに到達した。 Through various examinations and verifications as described above, a new concept has been reached in which the tripod member is made of a relatively inexpensive chrome steel and the heat treatment deformation of the female spline is suppressed by a normal heat treatment in which the entire surface is carburized and quenched and tempered.
図19に、第1の実施形態のトリポード型等速自在継手1を組込んだ自動車のフロント用ドライブシャフト50を示す。図19において、ドライブシャフト50の左側が駆動車輪側(アウトボード側)で右側がデフ側(インボード側)である。摺動式のトリポード型等速自在継手1は、シャフト9のインボード側端部に連結され、固定式のツェッパ型等速自在継手31は、シャフト9のアウトボード側端部に連結されている。ツェッパ型等速自在継手31の外周面とシャフト9の外周面との間、およびトリポード型等速自在継手1の外周面とシャフト9の外周面との間に、それぞれ蛇腹状ブーツ52、53がブーツバンド54a、54b、54c、54dにより締付固定されている。継手内部には潤滑剤としてのグリースが封入されている。 FIG. 19 shows a front drive shaft 50 of an automobile incorporating the tripod type constant velocity universal joint 1 of the first embodiment. In FIG. 19, the left side of the drive shaft 50 is the drive wheel side (outboard side) and the right side is the differential side (inboard side). The sliding tripod type constant velocity universal joint 1 is connected to the inboard side end portion of the shaft 9, and the fixed Rzeppa type constant velocity universal joint 31 is connected to the outboard side end portion of the shaft 9. . Bellows-shaped boots 52 and 53 are respectively provided between the outer peripheral surface of the Rzeppa constant velocity universal joint 31 and the outer peripheral surface of the shaft 9 and between the outer peripheral surface of the tripod type constant velocity universal joint 1 and the outer peripheral surface of the shaft 9. It is fastened and fixed by boot bands 54a, 54b, 54c, 54d. Grease as a lubricant is sealed inside the joint.
ツェッパ型等速自在継手31の内側継手部材32とトリポード型等速自在継手1のトリポード部材3は、それぞれ、シャフト9にスプライン嵌合で連結されている。前述したように、トリポード部材3は、クロム鋼からなり、全面浸炭焼入れ焼戻しによる硬化層が形成され、雌スプライン23は、その小径部の真円度が20μm以下の精度の高いスプラインで形成されている。このため、シャフト9の雄スプライン24との間でスプラインの各歯に作用する応力を可及的に均一化し、高強度なスプライン嵌合を実現する。また、比較的安価なクロム鋼を用い全面浸炭焼入れ焼戻しを施しているので、加工時間の増加やコスト増加を抑制でき、ひいては、ドライブシャフト50の低コストを図ることができる。 The inner joint member 32 of the Rzeppa type constant velocity universal joint 31 and the tripod member 3 of the tripod type constant velocity universal joint 1 are respectively connected to the shaft 9 by spline fitting. As described above, the tripod member 3 is made of chromium steel, a hardened layer is formed by carburizing, quenching, and tempering the entire surface, and the female spline 23 is formed of a highly accurate spline having a roundness of a small diameter portion of 20 μm or less. Yes. For this reason, the stress acting on each tooth of the spline is made as uniform as possible with the male spline 24 of the shaft 9 to realize high-strength spline fitting. Further, since the entire carburizing quenching and tempering is performed using relatively inexpensive chrome steel, an increase in processing time and an increase in cost can be suppressed, and consequently, the cost of the drive shaft 50 can be reduced.
次に、本発明に係るトリポード型等速自在継手の第2の実施形態を図20〜22に基づいて説明する。図20は、本実施形態のトリポード型等速自在継手の部分縦断面図であり、図21は、トリポード部材の正面図である。図20に示すように、トリポード型等速自在継手61はシングルローラタイプのものである。このトリポード型等速自在継手61は、外側継手部材62、内方部材としてのトリポード部材63、トルク伝達要素としての転動体65および球面ローラ64を主な構成とする。外側継手部材62の内周部に3本のトラック溝66が軸方向に形成され、各トラック溝66の両側にそれぞれローラ案内面67が軸方向に形成されている。 Next, a second embodiment of the tripod type constant velocity universal joint according to the present invention will be described with reference to FIGS. FIG. 20 is a partial longitudinal sectional view of the tripod type constant velocity universal joint of the present embodiment, and FIG. 21 is a front view of the tripod member. As shown in FIG. 20, the tripod constant velocity universal joint 61 is of a single roller type. The tripod type constant velocity universal joint 61 mainly includes an outer joint member 62, a tripod member 63 as an inward member, a rolling element 65 as a torque transmission element, and a spherical roller 64. Three track grooves 66 are formed in the axial direction on the inner peripheral portion of the outer joint member 62, and roller guide surfaces 67 are formed in the axial direction on both sides of each track groove 66.
トリポード部材63は、そのボス部63aより3本の脚軸63bが放射状に形成されている。脚軸63bに多数の転動体65を介して球面ローラ64が嵌合され、転動体の両端にワッシャ69、70を介在させ、ワッシャ69は止め輪68により位置決めされている。脚軸63bの外径面は転動体65の内側軌道面を形成し、球面ローラ64の内径面は転動体65の外側軌道面を形成している。転動体65の列が脚軸63b上で案内されると共に、球面ローラ64は、転動体65上で回転自在で、かつ脚軸63bの軸線方向に移動可能となっている。また、球面ローラ64は、外側継手部材62のローラ案内面67に回転自在に収容されている。このような構造により、外側継手部材62とトリポード部材63との間の相対的な軸方向変位や角度変位が吸収され、回転が等速で伝達される。 The tripod member 63 has three leg shafts 63b formed radially from the boss portion 63a. A spherical roller 64 is fitted to the leg shaft 63b via a large number of rolling elements 65, and washers 69, 70 are interposed at both ends of the rolling elements, and the washer 69 is positioned by a retaining ring 68. The outer diameter surface of the leg shaft 63 b forms the inner raceway surface of the rolling element 65, and the inner diameter surface of the spherical roller 64 forms the outer raceway surface of the rolling element 65. The row of rolling elements 65 is guided on the leg shaft 63b, and the spherical roller 64 is rotatable on the rolling element 65 and is movable in the axial direction of the leg shaft 63b. The spherical roller 64 is rotatably accommodated on the roller guide surface 67 of the outer joint member 62. With such a structure, relative axial displacement and angular displacement between the outer joint member 62 and the tripod member 63 are absorbed, and rotation is transmitted at a constant speed.
トリポード部材63のボス部63aの内周面72に雌スプライン73が形成され、この雌スプライン73とシャフト81の雄スプライン74が嵌合され、トルク伝達可能に連結されている。 A female spline 73 is formed on the inner peripheral surface 72 of the boss portion 63a of the tripod member 63, and the female spline 73 and the male spline 74 of the shaft 81 are fitted and connected so as to transmit torque.
図21にトリポード部材63の正面図を拡大して示す。トリポード部材63は、ボス部63aから3本の脚軸63bが放射状に突出し、転動体65の内側軌道面となる脚軸63bの外径面63cは、例えば、研削加工により仕上げられている。ボス部63aの内周面72に雌スプライン73が形成されている。本実施形態に適用されるトリポード部材63は、第1の実施形態と同様、クロム鋼(例えば、SCr420)からなり、全面浸炭焼入れ焼戻しによる硬化層が表面全体に形成されている。雌スプライン73は、熱処理変形が抑制され、真円度の高いピッチ円Pを有し、雌スプライン73の小径部73aの真円度が20μm以下の精度の高いスプラインで形成されている。したがって、雌スプライン73にシャフト81の雄スプライン74を嵌合してトルクを伝達するとき、各スプライン73、74の各歯に作用する応力は可及的に均一になる。 FIG. 21 is an enlarged front view of the tripod member 63. In the tripod member 63, three leg shafts 63b project radially from the boss portion 63a, and the outer diameter surface 63c of the leg shaft 63b serving as the inner raceway surface of the rolling element 65 is finished by, for example, grinding. A female spline 73 is formed on the inner peripheral surface 72 of the boss portion 63a. Similar to the first embodiment, the tripod member 63 applied to the present embodiment is made of chromium steel (for example, SCr420), and a hardened layer is formed on the entire surface by carburizing and tempering the entire surface. The female spline 73 is formed of a highly accurate spline in which heat treatment deformation is suppressed, the pitch circle P has a high roundness, and the roundness of the small-diameter portion 73a of the female spline 73 is 20 μm or less. Therefore, when the male spline 74 of the shaft 81 is fitted to the female spline 73 and torque is transmitted, the stress acting on the teeth of the splines 73 and 74 becomes as uniform as possible.
本実施形態に適用されるトリポード部材63の製造方法は、前述した製造方法についての実施形態と同様であるので、前述した内容を準用し、説明を省略する。また、本実施形態に適用されるトリポード部材63の雌スプライン73の小径部の真円度の測定方法および測定結果は、トリポード型等速自在継手についての第1の実施形態と同様であるので、前述した内容を準用し、説明を省略する。 Since the manufacturing method of the tripod member 63 applied to this embodiment is the same as that of embodiment about the manufacturing method mentioned above, the content mentioned above is applied mutatis mutandis and description is abbreviate | omitted. Moreover, since the measuring method and measurement result of the roundness of the small diameter part of the female spline 73 of the tripod member 63 applied to this embodiment are the same as those of the first embodiment for the tripod type constant velocity universal joint, The above description applies mutatis mutandis and description is omitted.
図22に、第2の実施形態のトリポード型等速自在継手61を組込んだ自動車のフロント用ドライブシャフト80を示す。図22においても、ドライブシャフト80の左側が駆動車輪側(アウトボード側)で右側がデフ側(インボード側)である。摺動式のトリポード型等速自在継手61は、シャフト81のインボード側端部に連結され、固定式のツェッパ型等速自在継手51は、シャフト81のアウトボード側端部に連結されている。このドライブシャフト80に使用されたシャフト81は中空シャフトである。ツェッパ型等速自在継手51の外周面とシャフト81の外周面との間、およびトリポード型等速自在継手61の外周面とシャフト81の外周面との間に、それぞれ蛇腹状ブーツ82、83がブーツバンド84a、84b、84c、84dにより締付固定されている。継手内部には潤滑剤としてのグリースが封入されている。 FIG. 22 shows a front drive shaft 80 of an automobile incorporating the tripod constant velocity universal joint 61 according to the second embodiment. Also in FIG. 22, the left side of the drive shaft 80 is the drive wheel side (outboard side) and the right side is the differential side (inboard side). The sliding tripod type constant velocity universal joint 61 is connected to the inboard side end portion of the shaft 81, and the fixed type topper type constant velocity universal joint 51 is connected to the outboard side end portion of the shaft 81. . The shaft 81 used for the drive shaft 80 is a hollow shaft. Bellows-like boots 82 and 83 are provided between the outer peripheral surface of the Rzeppa type constant velocity universal joint 51 and the outer peripheral surface of the shaft 81 and between the outer peripheral surface of the tripod type constant velocity universal joint 61 and the outer peripheral surface of the shaft 81, respectively. It is fastened and fixed by boot bands 84a, 84b, 84c, 84d. Grease as a lubricant is sealed inside the joint.
ツェッパ型等速自在継手51の内側継手部材52とトリポード型等速自在継手61のトリポード部材63は、それぞれ、シャフト81にスプライン嵌合で連結されている。トリポード部材63は、第1の実施形態と同様、クロム鋼からなり、全面浸炭焼入れ焼戻しによる硬化層が形成され、雌スプライン73は、その小径部の真円度が20μm以下の精度の高いスプラインで形成されている。このため、シャフト81の雄スプライン74との間でスプラインの各歯に作用する応力を可及的に均一化し、高強度なスプライン嵌合を実現する。また、比較的安価なクロム鋼を用い全面浸炭焼入れ焼戻しを施しているので、加工時間の増加やコスト増加を抑制でき、ひいては、ドライブシャフト80の低コストを図ることができる。 The inner joint member 52 of the Rzeppa type constant velocity universal joint 51 and the tripod member 63 of the tripod type constant velocity universal joint 61 are respectively connected to the shaft 81 by spline fitting. Similar to the first embodiment, the tripod member 63 is made of chromium steel, and a hardened layer is formed by carburizing and tempering the entire surface. The female spline 73 is a highly accurate spline with a roundness of a small diameter portion of 20 μm or less. Is formed. For this reason, the stress which acts on each tooth of a spline between the male splines 74 of the shaft 81 is made as uniform as possible, and high-strength spline fitting is realized. Further, since the entire carburizing quenching and tempering is performed using relatively inexpensive chrome steel, an increase in processing time and an increase in cost can be suppressed, and consequently, the cost of the drive shaft 80 can be reduced.
以上の実施形態では、トリポード部材3、63の材料であるクロム鋼について、SCr420材を例示したが、これに限られず、SCr415材やこれらに相当する材料を使用することができる。相当する材料としては、例えば、ISO規格の20Cr4材、20CrS4材や、SAE規格の5120材、DIN規格の17Cr3材、17CrS3材などが挙げられる。 In the above embodiment, although the SCr420 material was illustrated about the chromium steel which is the material of the tripod members 3 and 63, it is not restricted to this, An SCr415 material and the material equivalent to these can be used. Examples of the corresponding material include ISO standard 20Cr4 material, 20CrS4 material, SAE standard 5120 material, DIN standard 17Cr3 material, and 17CrS3 material.
また、本発明は前述した実施形態に何ら限定されるものではなく、本発明の要旨を逸脱しない範囲内において、さらに種々の形態で実施し得ることは勿論のことであり、本発明の範囲は、特許請求の範囲によって示され、さらに特許請求の範囲に記載の均等の意味、および範囲内のすべての変更を含む。 The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the spirit of the present invention. All equivalents and equivalents of the claims, and all modifications within the scope of the claims are embraced by the claims.
1 トリポード型等速自在継手
2 外側継手部材
3 トリポード部材
3a ボス部
4 ローラユニット
5 トラック溝
6 ローラ案内面
7 脚軸
8 シャフト
11 ローラ(アウタリング)
23 雌スプライン
23a 小径部
61 トリポード型等速自在継手
62 外側継手部材
63 トリポード部材
63a ボス部
63b 脚軸
64 球面ローラ
65 針状ころ
66 トラック溝
67 ローラ案内面
73 雌スプライン
73a 小径部
81 シャフト
C 円筒状部位
D 脚軸形成部位
DESCRIPTION OF SYMBOLS 1 Tripod type constant velocity universal joint 2 Outer joint member 3 Tripod member 3a Boss part 4 Roller unit 5 Track groove 6 Roller guide surface 7 Leg shaft 8 Shaft 11 Roller (outer ring)
23 Female spline 23a Small diameter portion 61 Tripod type constant velocity universal joint 62 Outer joint member 63 Tripod member 63a Boss portion 63b Leg shaft 64 Spherical roller 65 Needle roller 66 Track groove 67 Roller guide surface 73 Female spline 73a Small diameter portion 81 Shaft C Cylindrical -Shaped part D Leg axis forming part
Claims (6)
前記トリポード部材は、クロム鋼からなり、全面浸炭焼入れ焼戻しによる硬化層が形成され、
前記雌スプラインは、その小径部の真円度が20μm以下の精度の高いスプラインで形成されていることを特徴とするトリポード型等速自在継手。 An outer joint member having a track groove extending in the axial direction at a circumferentially divided position, a tripod member having a leg shaft protruding in a radial direction from the circumferentially divided position of the boss portion, and the leg A tripod type constant velocity universal joint including a roller rotatably mounted on a shaft, the roller being accommodated in the track groove, and a female spline for connecting to a shaft being formed on an inner peripheral surface of the boss portion. ,
The tripod member is made of chrome steel, and a hardened layer is formed by carburizing and tempering the entire surface,
The female spline is a tripod type constant velocity universal joint characterized in that it is formed of a highly accurate spline having a roundness of a small diameter portion of 20 μm or less.
前記トリポード部材のビレットとしてクロム鋼からなるバー材を切断する工程と、
前記ビレットを、フェライトとパーライトの整粒化された金属組織にする完全焼なましを施す工程と、
その後、前記ビレットを冷間閉塞鍛造により前記トリポード部材の素形材を形成する工程と、
前記素形材に旋削加工および雌スプラインの加工を施してトリポード部材を形成する工程と、
その後、このトリポード部材を全面浸炭焼入れ焼戻しする工程とを備えていることを特徴とするトリポード型等速自在継手のトリポード部材の製造方法。 An outer joint member having a track groove extending in the axial direction at a circumferentially divided position, a tripod member having a leg shaft protruding in a radial direction from the circumferentially divided position of the boss portion, and the leg A tripod type constant velocity universal joint that includes a roller rotatably mounted on a shaft, the roller is accommodated in the track groove, and a female spline is formed on the inner peripheral surface of the boss portion to be connected to the shaft. In the manufacturing method of the tripod member,
Cutting the bar material made of chrome steel as the billet of the tripod member;
A step of subjecting the billet to a complete annealing of ferrite and pearlite into a sized metal structure; and
Thereafter, the billet is formed by forming the tripod member by cold closed forging,
Forming a tripod member by subjecting the base material to turning and female spline processing;
Then, the manufacturing method of the tripod member of a tripod type constant velocity universal joint characterized by including the process of carburizing quenching and tempering the entire surface of this tripod member.
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JP2001208091A (en) * | 2000-01-27 | 2001-08-03 | Ntn Corp | Constant speed universal coupling |
JP2008144226A (en) * | 2006-12-08 | 2008-06-26 | Jfe Steel Kk | Constant-velocity universal joint excellent in rolling fatigue characteristic, and its manufacturing method |
JP2010261559A (en) * | 2009-05-11 | 2010-11-18 | Ntn Corp | Trunnion for tripod type constant velocity universal coupling, and tripod type constant velocity universal coupling |
JP2011226589A (en) * | 2010-04-21 | 2011-11-10 | Ntn Corp | Tripod type constant velocity universal joint and outside joint member for the same |
JP2013217478A (en) * | 2012-04-11 | 2013-10-24 | Ntn Corp | Inner member of constant velocity universal joint, and method for producing same |
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JP2001208091A (en) * | 2000-01-27 | 2001-08-03 | Ntn Corp | Constant speed universal coupling |
JP2008144226A (en) * | 2006-12-08 | 2008-06-26 | Jfe Steel Kk | Constant-velocity universal joint excellent in rolling fatigue characteristic, and its manufacturing method |
JP2010261559A (en) * | 2009-05-11 | 2010-11-18 | Ntn Corp | Trunnion for tripod type constant velocity universal coupling, and tripod type constant velocity universal coupling |
JP2011226589A (en) * | 2010-04-21 | 2011-11-10 | Ntn Corp | Tripod type constant velocity universal joint and outside joint member for the same |
JP2013217478A (en) * | 2012-04-11 | 2013-10-24 | Ntn Corp | Inner member of constant velocity universal joint, and method for producing same |
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JP2020106087A (en) * | 2018-12-27 | 2020-07-09 | Ntn株式会社 | Tripod-type constant velocity universal joint |
CN113195915A (en) * | 2018-12-27 | 2021-07-30 | Ntn株式会社 | Tripod type constant velocity universal joint |
JP7358046B2 (en) | 2018-12-27 | 2023-10-10 | Ntn株式会社 | Tripod type constant velocity universal joint |
US12038050B2 (en) | 2018-12-27 | 2024-07-16 | Ntn Corporation | Tripod-type constant velocity universal joint |
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