JPH0466239A - Method for form-rolling axial billet to be form-rolled - Google Patents

Abstract

PURPOSE:To improve strength without weakening the tooth form end part by concentration of stress because diameter is nearly equal over the total length of the perfect tooth form part to the axial part by form-rolling a tooth form part, then, gradually form-rolling the tooth form end part to form a tooth form. CONSTITUTION:When a form-rolling die 1 is moved toward a billet 3 to be form-rolled, at first, a part A of a group 2a of biting teeth comes in contact with the 3a' of the billet 3 to be form-rolled and roll-forming is begun as the bearing to the contact surface is elevated gradually. When the form-rolling die 1 moves to a part B of the group 2a of biting teeth, the formed chamfering part 5 comes gradually in contact with the part 3b. When the formed chamfering part 5 comes in contact with the part 3b' and pressing is begun, a partial force to escape the billet 3 to be form-rolled in the axial direction is generated and since the group 2a of biting teeth has already bitten into the part 3a', the billet 3 to be roll-formed does not deviate from a normal position.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、軸状被転造素材の外周にスプラインやセレー
ション等の歯形を転造形成する方法に関し、特に、被転
造素材の強度向上を図ったものに関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for rolling forming tooth profiles such as splines and serrations on the outer periphery of a shaft-shaped material to be rolled, and in particular, to a method for rolling forming tooth profiles such as splines and serrations on the outer periphery of a material to be rolled. Regarding things that aim to.

〔従来の技術〕[Conventional technology]

軸状被転造素材の外周にスプラインやセレーション等の
歯形を形成する方法として、転造加工法がよく用いられ
ている。これは、ホブ等を用いて歯切りをおこなう加工
方法に比べて生産性が高いことによる。A rolling method is often used to form tooth profiles such as splines and serrations on the outer periphery of a shaft-shaped material to be rolled. This is because the productivity is higher than the machining method in which gear cutting is performed using a hob or the like.

第１図は、ランク型の転造ダイスを用いた転造加工法を
示す。この方法は、転造歯形（２）を形成した２つの転
造ダイス（１）（１）間に軸状の被転造素材（３）を配
し、転造ダイス（１）（１）を被転造素材（３）に押圧
しながら夫々を矢印の方向に相対移動させて、被転造素
材（３）の外周面を転造歯形（２）により塑性変形させ
る。加゛工時に、転造歯形（２）の歯先（２ｔ）が被転
造素材（３）にくい込むため、第７Ａ図及び第７Ｂ図に
示す様に、転造歯形（２）の側端部に歯先（２ｔ）に曲
率をもたせた面取り部（５）を設けて、歯端面と被転造
素材（３）との干渉を回避させている。FIG. 1 shows a rolling method using a rank-type rolling die. In this method, a shaft-shaped material to be rolled (3) is placed between two rolling dies (1) (1) that have formed a rolling tooth profile (2), and the rolling dies (1) (1) are The material to be rolled (3) is moved relative to each other in the direction of the arrow while being pressed against the material to be rolled (3), and the outer circumferential surface of the material to be rolled (3) is plastically deformed by the rolling tooth profile (2). During machining, the tooth tip (2t) of the rolled tooth profile (2) bites into the material to be rolled (3), so as shown in Figures 7A and 7B, the side edge of the rolled tooth profile (2) A chamfered portion (5) with a curvature at the tooth tip (2t) is provided at the tooth tip (2t) to avoid interference between the tooth end surface and the material to be rolled (3).

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

第８図は、前述した転造加工法を用いて転造した被転造
素材（３）を示す。転造歯形により押し除けられた被転
造素材（３）の肉は、外径方向と軸方向に移動して盛り
上がり、完全歯形（３ａ）および歯形切り上げ部（３ｂ
）を形成する。このため、完全歯形（３ａ）の歯先径（
Ｄａ）は軸部径（Ｄｃ）よりも大きくなり、歯底径（Ｄ
’ａ　）は軸部径（Ｄｃ）よりも小さくなる。そして、
完全歯形（３ａ）の歯先及び歯底は、歯形切り上げ部（
３ｂ）でその径を変化させて軸部（３ｃ）に連続する。FIG. 8 shows a material to be rolled (3) that has been rolled using the above-described rolling method. The flesh of the material to be rolled (3) pushed away by the rolling tooth profile moves in the outer radial direction and axial direction and bulges, resulting in a complete tooth profile (3a) and a raised tooth profile (3b).
) to form. For this reason, the tooth tip diameter (
Da) is larger than the shaft diameter (Dc), and the tooth root diameter (D
'a) is smaller than the shaft diameter (Dc). and,
The tip and bottom of the complete tooth profile (3a) are rounded-up portions of the tooth profile (3a).
3b) changes its diameter and continues to the shaft portion (3c).

このように、歯形切り上げ部（３ｂ）は素材径の変化点
になるため、この部分に応力が集中しやすくなり、強度
が不足する場合がある。In this way, since the tooth profile rounded-up portion (3b) is a point of change in the material diameter, stress tends to concentrate at this portion, which may result in insufficient strength.

そこで、本発明は歯形転造加工に伴う被転造素材の強度
低下を防止することをその目的とする。Therefore, an object of the present invention is to prevent the strength reduction of the material to be rolled due to the tooth profile rolling process.

〔課題を解決するための手段〕[Means to solve the problem]

本発明では、小径の歯形部から大径の軸部に歯形切り上
げ部を漸次拡径させて連続させた被転造素材と、転造歯
形の側端部に歯先、ピッチ線、歯底に曲率をもたせた総
形面取り部を形成した転造ダイスとを用いて、歯形部の
みの転造から始め、その後に歯形切り上げ部も徐々に転
造して歯形を形成するようにした。In the present invention, the material to be rolled is formed by gradually increasing the diameter of the tooth profile cut-up part from the small diameter tooth profile part to the large diameter shaft part, and forming the tooth tip, pitch line, and tooth bottom at the side end of the rolled tooth profile. Using a rolling die with a fully chamfered portion with curvature, rolling was started with only the tooth profile portion, and then the rounded-up portion of the tooth profile was also gradually rolled to form the tooth profile.

〔作用〕[Effect]

転造ダイスを被転造素材に押圧すると、転造歯形により
押し除けられた素材の肉が、外径方向と軸方向に移動し
て歯形を形成する。When the rolling die is pressed against the material to be rolled, the material of the material pushed away by the rolling tooth profile moves in the outer radial direction and axial direction to form the tooth profile.

被転造素材の歯形部においては、この部位の径を軸部の
径よりも小さくしであるために、歯先を盛り上げること
により、歯先径を軸部の径と同等にすることができる。In the tooth profile of the material to be rolled, the diameter of this part is smaller than the diameter of the shaft, so by raising the tooth tip, the diameter of the tooth tip can be made equal to the diameter of the shaft. .

また、歯形切り上げ部においては、この部位を総形面取
り部で押圧し、歯先を総形面取り部の歯底形状に対応さ
せて盛り上げることにより、歯先径を歯形部の歯先径と
同等以上にすることができる。転造ダイスの総形面取り
部においては、外径方向に移動する素材の肉と軸方向に
移動して来る素材の肉とが合流して歯底に向かって盛り
上がるが、歯底に曲率をもたせであるためにトフブロー
リング（歯底と転造内との干渉）が回避される。In addition, in the rounded-up part of the tooth profile, by pressing this part with the full chamfer and raising the tooth tip to correspond to the bottom shape of the full chamfer, the tooth tip diameter is made equal to the tooth tip diameter of the tooth profile part. You can do more than that. At the general chamfer of a rolling die, the material moving in the outer diameter direction and the material moving in the axial direction merge and bulge toward the tooth bottom, but the tooth bottom has a curvature. Therefore, tofu rolling (interference between the tooth bottom and the inside of the rolling) is avoided.

このようにすることによって、歯形切り上げ部の窟みが
なくなり、歯形切り上げ部における応力集中が回避され
る。By doing this, there is no recess in the rounded-up portion of the tooth profile, and stress concentration at the rounded-up portion of the tooth profile is avoided.

また、総形面取り部が歯形切り上げ部の転造を始めると
、歯形切り上げ部が漸次拡径する形状をもつため、転造
ダイスの押圧力の一部が軸方向の分力となって被転造素
材を軸方向に逃がそうとするが、転造ダイスは即に歯形
部にくい込んでいるため、被転造素材の位置ずれがおこ
らない。In addition, when the total chamfer starts rolling the tooth profile cut-up part, the tooth profile cut-up part has a shape that gradually expands in diameter, so a part of the pressing force of the rolling die becomes an axial component force and is rolled. Although an attempt is made to release the forming material in the axial direction, the rolling die is immediately embedded in the tooth profile, so the position of the material to be rolled does not shift.

〔実施例〕〔Example〕

以下、本発明の実施例を図面に基づいて説明する。 Embodiments of the present invention will be described below based on the drawings.

本発明に係る転造方法は、第１図に示す方法と同様に、
２つの転造ダイス（１）（１）を用いて、軸状の被転造
素材（３）を転造加工する。The rolling method according to the present invention is similar to the method shown in FIG.
A shaft-shaped material to be rolled (3) is rolled using two rolling dies (1) (1).

第２Ａ図及び第２Ｂ図は、本実施例で用いる転造ダイス
（１）を示す。転造ダイス（１）の上面には転造歯形（
２）が形成されている。この転造歯形（２）は、歯高さ
をダイス中央に向かって漸増させる食付き歯群（２ａ）
　、一定の歯高さを有する仕上げ歯群（２ｂ）　、歯高
さをダイス端面に向かって漸減させる逃げ歯群（２Ｃ）
とからなり、転造歯形（２）の側端部には、食付き歯群
（２ａ）から仕上げ歯群（２ｂ）の終端付辺までにわた
って総形面取り部（５）が形成されている。総形面取り
部（５）は第２Ｃ図に示す様に、転造歯形（２）の歯先
（２ｔ）　、ピッチ線（２Ｐ）　、歯底（２ｒ）に曲率
をもたせたもので、食付き歯群（２ａ）の中央付込まで
（Ａ部とする）面取り巾を大きく（Ｗｌ）とり、中央部
付込から（Ｂ部とする）漸減させて一定の巾Ｗ２にしで
ある。Figures 2A and 2B show the rolling die (1) used in this example. The rolling die (1) has a rolling tooth profile (
2) is formed. This rolled tooth profile (2) has a chamfered tooth group (2a) whose tooth height gradually increases toward the center of the die.
, a finishing tooth group (2b) having a constant tooth height, and a relief tooth group (2C) whose tooth height gradually decreases toward the die end surface.
A full chamfered portion (5) is formed at the side end of the rolled tooth profile (2) extending from the chamfered tooth group (2a) to the terminal side of the finished tooth group (2b). As shown in Fig. 2C, the full chamfered portion (5) has curvature on the tooth tip (2t), pitch line (2P), and tooth bottom (2r) of the rolled tooth profile (2). The chamfer width is increased (Wl) at the center insertion of the tooth group (2a) (referred to as part A), and is gradually decreased from the center insertion (referred to as part B) to a constant width W2.

また、転造歯形（２）の側端部には、仕上げ歯群（２ｂ
）の終端付辺から逃げ歯群（２Ｃ）にわたって、歯底（
２ｒ）と同−面又は少し低い面とした平面部（６）が形
成されている。尚、平面部（６）の巾Ｗ３は、総形面取
り部（５）の面取り巾Ｗ２より若干大きくしである。In addition, at the side end of the rolled tooth profile (2), a group of finished teeth (2b
) from the terminal side to the relief tooth group (2C), the bottom of the tooth (
A flat portion (6) is formed which is on the same level as or slightly lower than 2r). Note that the width W3 of the flat portion (6) is slightly larger than the chamfer width W2 of the full-length chamfered portion (5).

第３図は、被転造素材（３）を示す。被転造素材（３）
は、小径の歯形部（以下、３ａ１部と略す）から大径の
軸部（３ｃ）に歯形切り上げ部（以下、３ｂ’部と称す
）を漸次拡径させて連続させたものである。３ａ°　部
の径Ｄａ’及び３ｂ’部の径Ｄｂ’　は、軸部（３ｃ）
の径Ｄｃから形成すべき歯形の盛り上げ高さを考慮して
決定する。FIG. 3 shows the material to be rolled (3). Rolled material (3)
In this case, a tooth profile cut-up portion (hereinafter referred to as 3b' portion) is continuous from a small diameter tooth portion (hereinafter abbreviated as 3a1 portion) to a large diameter shaft portion (3c) by gradually increasing the diameter. The diameter Da' of the 3a° part and the diameter Db' of the 3b' part are the diameter of the shaft part (3c).
The height of the tooth profile to be formed is determined based on the diameter Dc.

第４図は、被転造素材（３）に歯形が形成されてゆく状
態を段階的に示す。FIG. 4 shows step by step the state in which a tooth profile is formed on the material to be rolled (3).

同図Ａ： 転造ダイス（１）を被転造素材（３）に向けて移動させ
ると、まず、食付き歯群（２ａ）のＡ部が被転造素材（
３）の３ａ’部に接触し、接触面圧を徐々に高めなから
転造を始める。Figure A: When the rolling die (1) is moved toward the material to be rolled (3), first, part A of the chamfered tooth group (2a) touches the material to be rolled (3).
Contact the part 3a' of 3) and start rolling while gradually increasing the contact surface pressure.

Ａ部においては、面取り巾を太きく　　（Ｗｌ）とっで
あるために、総形面取り部（５）は３ｂ’部と接触して
いない。In part A, since the chamfer width is set wide (Wl), the full-form chamfer part (5) does not contact part 3b'.

同図Ｂ： 転造ダイス（１）が食付き歯群（２ａ）のＢ部まで移動
すると、総形面取り部（５）の面取り巾が漸減するため
、総形面取り部（５）は３ｂ’部と徐々に接触してゆき
、Ｂ部の終端（Ｗ２）で完全に接触する。総形面取り部
（５）が３ｂ’部に接触し押圧を始めると、被転造素材
（３）を軸方向に逃がそうとする分力が発生するが、こ
の時、食い付歯群（２ａ）が既に３ａ１部にくい込んで
いるため、被転造素材（３）は位置ずれしない。Figure B: When the rolling die (1) moves to part B of the chamfered tooth group (2a), the chamfer width of the full chamfer (5) gradually decreases, so the full chamfer (5) becomes 3b' gradually comes into contact with the part B, and completely contacts at the end (W2) of part B. When the full-form chamfered part (5) comes into contact with the part 3b' and starts pressing, a component force is generated that tries to release the material to be rolled (3) in the axial direction, but at this time, the biting tooth group ( Since 2a) is already embedded in a portion of 3a, the material to be rolled (3) does not shift.

同図Ｃ： 転造ダイス（１）が仕上げ歯群（２ｂ）まで移動すると
、３８１部および３ｂ”部が盛り上がり、所定形状の完
全歯形（３ａ）および歯形切り上げ部（３ｂ）が形成さ
れる。完全歯形（３ａ）の歯先径（Ｄａ）は、軸部（３
ｃ）の径（Ｄｃ）と同等になる。この際、歯形切り上げ
部（３ｂ）の歯先径（Ｄｂ）が完全歯形（３ａ）の歯先
径（Ｄｃ）よりも僅かに大きくなるようにするのが望ま
しい。平面部（６）は、歯形切り上げ部（３ｂ）の歯先
が必要以上に盛り上がるのを抑制する作用をなす。ある
いは、平面部（６）を形成する代りに、第５図に示す様
に、盛り上がり気味に転造した歯形切り上げ部（３ｂ）
の歯先を、被転造素材（３）の回転を利用して、バイト
（７）により旋削加工するようにしてもよい。このよう
にしても、加工工程を増やすことにはならない。Figure C: When the rolling die (1) moves to the finishing tooth group (2b), the 381 section and the 3b'' section are raised to form a complete tooth profile (3a) and a tooth profile cut-up section (3b) of a predetermined shape. The tooth tip diameter (Da) of the complete tooth profile (3a) is
It is equivalent to the diameter (Dc) of c). At this time, it is desirable that the tooth tip diameter (Db) of the tooth profile rounded-up portion (3b) be slightly larger than the tooth tip diameter (Dc) of the complete tooth profile (3a). The flat portion (6) functions to prevent the tip of the tooth profile cut-up portion (3b) from protruding more than necessary. Alternatively, instead of forming a flat part (6), as shown in FIG. 5, a raised tooth profile part (3b) is formed.
The tip of the tooth may be turned by the cutting tool (7) by utilizing the rotation of the material to be rolled (3). Even if this is done, the number of processing steps will not be increased.

その後、転造ダイス（１）は逃げ歯群（２ｃ）まで移動
し、接触面圧を徐々に低めなから被転造素材（３）から
逃げてゆく。Thereafter, the rolling die (1) moves to the set of relief teeth (2c) and gradually lowers the contact surface pressure to escape from the material to be rolled (3).

以上、ラック型転造ダイスを用いた場合について説明し
たが、第６図に示す様に、転造歯形（２）の展開図が第
２Ａ図のようになる丸型の転造ダイスを用いることも勿
論可能である。The case where a rack-type rolling die is used has been described above, but as shown in Fig. 6, it is also possible to use a round-shaped rolling die in which the developed view of the rolling tooth profile (2) is as shown in Fig. 2A. Of course, it is also possible.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、歯形転造後の被転造素材が完全歯形か
ら軸部にわたってほぼ同径になるため・従来、歯形切り
上げ部への応力集中によって弱められていた素材強度を
向上させることができる。According to the present invention, since the material to be rolled after tooth profile rolling becomes approximately the same diameter from the complete tooth profile to the shaft portion, it is possible to improve the strength of the material, which was conventionally weakened by stress concentration on the rounded-up portion of the tooth profile. can.

また、本発明に係る転造方法は、歯形部の転造から始め
、その後に歯形切り上げ部を徐々に転造するため、転造
時に被転造素材の軸方向の位置すれかな（、精度の高い
歯形が形成される。In addition, the rolling method according to the present invention starts with rolling the tooth profile portion and then gradually rolls the tooth profile cut-up portion. A high tooth profile is formed.

【図面の簡単な説明】[Brief explanation of drawings]

第１図はラック型の転造ダイスを用いた転造方法を示す
略図、 第２Ａ図は転造ダイスの平面図、 第２Ｂ図は転造ダイスの側面図、 第２Ｃ図は第２八図のＣ−Ｃ断面図、 第３図は被転造素材を示す側面図、 第４図（Ａ）、（Ｂ）、および（Ｃ）は被転造素材の歯
形形成状態を段階的に示す一部断面図、第５図及び第６
図は本発明の他の実施例を示す略図、 第７Ａ図及び第７Ｂ図は従来の転造ダイスを示す斜視図
及び断面図、 第８図は従来の転造方法を用いて加工した被転造素材を
示す一部断面図である。 １−・・−転造ダイス ３−・被転造素材 ３ａ゛：歯形部 ３ｂ゛：歯形切り上げ部 ３ｃ：細部 ３ａ・−完全歯形 ３ｂ・・−歯形切り上げ部 ５−総形面取り部 ２−転造歯形 ２ｔ：歯先 ２ｒ：歯底 ２Ｐ：ピッチ線 特 代 許 出 理 願 人 人 工ヌテイエヌ株式会社 オーニスジー株式会社 江　　　原　　　省　　吾− 第５図 第６図Figure 1 is a schematic diagram showing a rolling method using a rack-type rolling die, Figure 2A is a plan view of the rolling die, Figure 2B is a side view of the rolling die, and Figure 2C is Figure 28. FIG. 3 is a side view showing the material to be rolled, and FIG. Partial sectional view, Figures 5 and 6
The figure is a schematic diagram showing another embodiment of the present invention, Figures 7A and 7B are perspective views and sectional views showing a conventional rolling die, and Figure 8 is a rolled workpiece processed using the conventional rolling method. It is a partial sectional view showing a building material. 1-...-Rolling die 3--Material to be rolled 3a': Tooth profile section 3b': Tooth profile rounded-up section 3c: Detail 3a...-Complete tooth profile 3b...-Tooth profile rounded-up section 5-Complete chamfer section 2-Rolling Denture shape 2t: Tooth tip 2r: Tooth bottom 2P: Pitch line Patent patent applicant Artificial NTE Co., Ltd. OrnisG Co., Ltd. Shogo Ehara - Figure 5 Figure 6

Claims (2)

【特許請求の範囲】[Claims] （１）転造歯形を形成した２つの転造ダイス間に軸状の
被転造素材を配し、転造ダイスを被転造素材に押圧しな
がら相対移動させることにより、被転造素材を回転させ
ながら歯形を形成する転造方法において、 小径の歯形部から大径の軸部に歯形切り上げ部を漸次拡
径させて連続させた被転造素材と、転造歯形の側端部に
歯先、ピッチ線、歯底に曲率をもたせた総径面取り部を
形成した転造ダイスとを用いて、歯形部のみの転造から
始め、その後に歯形切り上げ部も徐々に転造して歯形を
形成するようにした軸状被転造素材の歯形転造方法。(1) A shaft-shaped material to be rolled is placed between two rolling dies that have formed a rolling tooth profile, and the material to be rolled is moved relative to the material while pressing the rolling die. In the rolling method in which a tooth profile is formed while rotating, the material to be rolled is made by gradually increasing the diameter of the rounded-up part of the tooth profile from the small-diameter tooth profile part to the large-diameter shaft part, and the tooth profile is formed at the side end of the rolled tooth profile. Using a rolling die with a total diameter chamfer with curvature at the tip, pitch line, and tooth bottom, start rolling only the tooth profile, and then gradually roll the rounded-up part of the tooth profile to complete the tooth profile. A tooth profile rolling method for a shaft-shaped material to be rolled. （２）歯形部の歯先を軸部の径と同等に盛り上げると共
に、歯形切り上げ部の歯先を歯形部の歯先径と同等以上
に盛り上げるようにした請求項１の軸状被転造素材の歯
形転造方法。(2) The axially rolled material according to claim 1, wherein the tip of the tooth profile is raised to be equal to the diameter of the shaft portion, and the tip of the tooth profile of the rounded-up portion is raised to be equal to or greater than the diameter of the tip of the tooth profile. tooth profile rolling method.