JP2002227958A - Screw shaft for ball screw - Google Patents

Screw shaft for ball screw

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Publication number
JP2002227958A
JP2002227958A JP2001021001A JP2001021001A JP2002227958A JP 2002227958 A JP2002227958 A JP 2002227958A JP 2001021001 A JP2001021001 A JP 2001021001A JP 2001021001 A JP2001021001 A JP 2001021001A JP 2002227958 A JP2002227958 A JP 2002227958A
Authority
JP
Japan
Prior art keywords
screw
shaft
screw member
diameter
extension member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2001021001A
Other languages
Japanese (ja)
Other versions
JP4549549B2 (en
Inventor
Soichiro Oga
壮一郎 大賀
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsubaki Nakashima Co Ltd
Original Assignee
Tsubaki Nakashima Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tsubaki Nakashima Co Ltd filed Critical Tsubaki Nakashima Co Ltd
Priority to JP2001021001A priority Critical patent/JP4549549B2/en
Publication of JP2002227958A publication Critical patent/JP2002227958A/en
Application granted granted Critical
Publication of JP4549549B2 publication Critical patent/JP4549549B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide a screw shaft for a ball screw having an extension member connected to at least the end face or end part of a screw member, lowering production cost compared to conventional ones. SOLUTION: A screw member 2 and an extension member 3 are made of the same material. Before the extension member 3 is connected to the screw member 2, thread grooves are formed on the outer peripheral surface 2A of the screw member 2 over the length thereof, and the outer peripheral surface 2A is subjected to surface hardening and finish machining by induction hardening or carburizing. A circular hole 18 provided in an end face 19 of the extension member 3 is fitted by shrink fit into a protruded shaft 16 having a smaller diameter than the root diameter of the thread groove protruded on an end face 17 of the screw member 2 so that the end face 19 of the extension member 3 keeps close contact with the end face 17 of the screw member 2. After the shrink fit, a twist is applied to the extension member 3 in order to shift the phase of the extension member 3 to the screw member 2, and to produce abrasion. The extension member 3 is connected to the end face 17 of the screw member 2 by subjecting the fitting surface between the protruded shaft 16 and the circular hole 18, and the end face 17 of the screw member 2 and the end face 19 of the extension member 3 to be baked by the abrasion.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、工作機械、産業用
ロボット、半導体製造装置等の各種機械の送り運動、動
力伝達又は位置決め手段として広く用いられているボー
ルねじのねじ軸に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw shaft of a ball screw widely used as a feeding motion, power transmission or positioning means for various machines such as a machine tool, an industrial robot, and a semiconductor manufacturing apparatus.

【０００２】[0002]

【従来の技術】ボールねじは、周知のように、ねじ軸の
ねじ溝が転造加工によって形成される、いわゆる「転造
ボールねじ」と、ねじ軸のねじ溝が切削及び研削加工に
よって形成される、いわゆる「研削ボールねじ」とに大
別される。また、一般に、「転造ボールねじ」及び「研
削ボールねじ」の精度は、それぞれ、JIS B 1192-1997
（ボールねじ）に規定される「等級Ｃ７，Ｃ１０」及び
「等級Ｃ０，Ｃ１，Ｃ３，Ｃ５」に準じている。そし
て、ボールねじを使用する場合、ねじ軸を片持支持して
回転駆動させるときは、一方の軸端（駆動側の軸端）に
選定した転がり軸受が嵌入される支持部と部品取付部が
形成される。また、ねじ軸を両端支持して回転駆動させ
るときは、一方の軸端（駆動側の軸端）に支持部と部品
取付部が形成され、他方の軸端（反駆動側の軸端）に支
持部が形成される（例えば、本出願人発行（1996．4．
1）「TSUBAKI NAKASHIMA 総合カタログ ７０（以下、
「総合カタログ」という。） 」A-12，A-18〜A-19，及
びA-197頁参照）。2. Description of the Related Art As is well known, a ball screw has a so-called "rolled ball screw" in which a thread groove of a screw shaft is formed by rolling, and a thread groove of a screw shaft is formed by cutting and grinding. This is roughly divided into so-called “ground ball screws”. Generally, the accuracy of the “rolled ball screw” and the “ground ball screw” is JIS B 1192 -1997
(Ball screw) "Grades C7, C10" and "Grades C0, C1, C3, C5". When a ball screw is used and the screw shaft is cantilevered and driven to rotate, the supporting portion and the component mounting portion into which the selected rolling bearing is fitted into one shaft end (the shaft end on the driving side) are fitted. It is formed. When the screw shaft is supported at both ends and driven to rotate, a support portion and a component mounting portion are formed at one shaft end (drive-side shaft end), and the other shaft end (non-drive-side shaft end) at the other end. A support portion is formed (for example, issued by the present applicant (1996.4.
1) TSUBAKI NAKASHIMA General Catalog 70 (hereinafter referred to as
"Comprehensive catalog". ) "On pages A-12, A-18 to A-19, and A-197).

【０００３】なお、転造ボールねじにおいては、後述の
製作工程によって、全長３ｍのねじ軸が在庫生産される
ことが多い。この在庫生産されたねじ軸は、砥石等によ
って旋削時の取りしろを残した所望の長さに切断されて
使用される。また、切断されたねじ軸の軸端は所定の長
さだけ焼ならし（例えば、アセチレンバーナで加熱後、
空気中で徐冷する。）された後、機械加工によって、こ
の軸端に所望の寸法・形状の支持部（及び部品取付部）
が形成される（一般に、「軸端追加工」と呼ばれてい
る。）。[0003] In a rolled ball screw, a screw shaft having a total length of 3 m is often produced in stock by a manufacturing process described later. The screw shaft produced in stock is used after being cut by a grindstone or the like into a desired length leaving a margin at the time of turning. In addition, the shaft end of the cut screw shaft is normalized by a predetermined length (for example, after heating with an acetylene burner,
Cool slowly in air. ), And then, by machining, this shaft end has a supporting part (and a part mounting part) of the desired size and shape.
Is formed (generally referred to as “shaft end additional processing”).

【０００４】次に、ボールねじのねじ軸の一般的な製作
工程を略述する。 （１）転造ボールねじのねじ軸（以下、「転造ねじ軸」
という。）所定の長さ（上述したように、３ｍとされる
ことが多い。）に切断された鋼丸棒（素材）を２丸形ダ
イス押付け式ねじ転造盤に装着された一対のロールダイ
ス間に挟み、通し転造によって外周面にねじ溝を全長に
亘って形成する。ねじ溝が形成された外周面を高周波焼
入れ又は浸炭焼入れによって表面硬化した後、焼戻しを
行う。そして、外周面をバフ仕上げする。 （２）研削ボールねじのねじ軸（以下、「研削ねじ軸」
という。） 所定の長さに切断された鋼丸棒（素材）の外周面及び両
端面を旋削加工して、仕上げ加工時の取りしろを残した
円筒部（ねじ溝が形成された後、「ねじ部」という。）
と軸端部を一体形成する。切削加工によって、円筒部の
外周面に研削仕上げ時の取りしろを残したねじ溝を形成
する（この「ねじ溝切削」は、焼戻し後に行われること
も多い。）。ねじ溝が形成されたねじ部の外周面を高周
波焼入れ又は浸炭焼入れによって表面硬化した後、焼戻
しを行う。ねじ部の外径を研削仕上げする。機械加工に
よって、軸端部に所望の寸法・形状の支持部（及び部品
取付部）を形成する。そして、ねじ溝を研削仕上げす
る。Next, a general manufacturing process of a screw shaft of a ball screw will be briefly described. (1) Rolled ball screw screw shaft (hereinafter “rolled screw shaft”
That. ) A steel round bar (material) cut to a predetermined length (often 3 m as described above) is placed between a pair of roll dies mounted on a two-round die pressing type screw rolling machine. And a thread groove is formed on the outer peripheral surface by thread rolling over the entire length. After the outer peripheral surface on which the thread groove is formed is hardened by induction hardening or carburizing quenching, tempering is performed. Then, the outer peripheral surface is buffed. (2) Screw shaft of grinding ball screw (hereinafter “grinding screw shaft”
That. After turning the outer peripheral surface and both end surfaces of a steel round bar (raw material) cut to a predetermined length, a cylindrical portion (after a thread groove is formed, leaving a margin for finishing) ")
And the shaft end are integrally formed. By the cutting process, a thread groove is formed on the outer peripheral surface of the cylindrical portion, leaving a margin at the time of the grinding finish (the “screw groove cutting” is often performed after tempering). After the outer peripheral surface of the thread portion having the thread groove formed is surface hardened by induction hardening or carburizing quenching, tempering is performed. Grind the outer diameter of the thread. A supporting portion (and a component mounting portion) having a desired size and shape is formed at the shaft end by machining. Then, the thread groove is ground.

【０００５】なお、 転造及び熱処理技術の向上によって、近時は、前述の
JIS B 1192 に規定される精度等級Ｃ３，Ｃ５の転造ね
じ軸を製作できるようになっている。このため、研削ボ
ールねじに比べて生産性が高く且つ製作コストが廉価な
転造ボールねじの需要は、従前以上に増加している。 転造ねじ軸及び研削ねじ軸の材質として、高周波焼入
れの場合は、一般に、調質炭素鋼Ｓ５５Ｃ又はＡＩＳＩ
４１５０Ｈが用いられる。また、浸炭焼入れの場合は、
一般に、調質クロムモリブデン肌焼鋼ＳＣＭ４１５Ｈ又
はＳＣＭ４２０Ｈが用いられる。さらに、焼戻し後のね
じ溝面の硬さ、すなわち、外周面の硬さはＨＲＣ５８〜
６２とされている。 研削ねじ軸において、ねじ部を高周波焼入れする場
合、ねじ部の軸端部近傍の焼入れが不完全になるから、
ねじ部有効長さを所望のナット移動距離より長くしなけ
ればならない（すなわち、ねじ軸の全長が長くな
る。）。また、ねじ部を浸炭焼入れする場合、軸端部近
傍までの完全焼入れは可能であるが、軸端部を防炭処理
（浸炭防止剤の塗布、又は銅メッキ）しなければならな
い。 転造ねじ軸及び研削ねじ軸のねじ溝は、一般に、ゴシ
ックアーク形状とされている。 転造ボールねじに予圧を付与する場合、転造ねじ軸の
バフ仕上げされたねじ溝を研削又はラップ加工すること
がある。In recent years, with the improvement of rolling and heat treatment techniques, recently,
Rolled screw shafts of accuracy classes C3 and C5 specified in JIS B 1192 can be manufactured. For this reason, the demand for the rolled ball screw which has higher productivity and lower production cost than the ground ball screw is increasing more than before. In the case of induction hardening, the material of the rolled screw shaft and the ground screw shaft is generally tempered carbon steel S55C or AISI.
4150H is used. In case of carburizing and quenching,
Generally, tempered chromium molybdenum case hardening steel SCM415H or SCM420H is used. Furthermore, the hardness of the thread groove surface after tempering, that is, the hardness of the outer peripheral surface is HRC58 ~
62. In case of induction hardening the threaded part of the ground screw shaft, the hardening near the shaft end of the threaded part becomes incomplete,
The effective length of the thread must be longer than the desired nut travel distance (ie, the overall length of the screw shaft is longer). Further, when carburizing and quenching the screw portion, complete quenching up to the vicinity of the shaft end is possible, but the shaft end must be carburized (application of a carburizing inhibitor or copper plating). Generally, the thread grooves of the rolled screw shaft and the ground screw shaft have a Gothic arc shape. When a preload is applied to a rolled ball screw, a buffed thread groove of a rolled screw shaft may be ground or lapped.

【０００６】ところで、転造ねじ軸における前述の軸端
追加工は、選定した転がり軸受が嵌入される支持部の軸
径がねじ溝の谷径より小さく、且つ、転がり軸受に対す
る支持部の肩の高さを軸受メーカー規定最小値以上に確
保できる場合（例えば、前述の「総合カタログ」A-222
〜A-225頁参照）に行われている。なお、肩の高さを十
分に確保するため、ねじ軸の外径より大径のカラーが支
持部に嵌入又は圧入されることも多い（研削ねじ軸にお
いても、上述の場合は同様である。）。[0006] By the way, in the above-mentioned additional machining of the shaft end of the rolled screw shaft, the shaft diameter of the support portion into which the selected rolling bearing is fitted is smaller than the root diameter of the thread groove, and the shoulder of the support portion with respect to the rolling bearing has When the height can be secured to the minimum value specified by the bearing manufacturer (for example, A-222
~ A-225 page). In addition, in order to secure a sufficient shoulder height, a collar having a diameter larger than the outer diameter of the screw shaft is often fitted or press-fitted into the support portion (the same applies to a ground screw shaft as well. ).

【０００７】他方、後述の図１に示すように、支持部の
軸径がねじ溝の谷径以上になる場合には、軸端追加工を
行うことができない。このような場合には、転造加工に
よって外周面にねじ溝が全長に亘って形成されたねじ部
材の少なくとも一方の端面に延設部材（研削ねじ軸にお
ける軸端部に相当。）を摩擦圧接によって接合した後、
機械加工によって、この延設部材に所望の寸法・形状の
支持部（及び部品取付部）が形成されている。なお、支
持部の軸径が、ねじ溝の谷径以上であることは言うまで
もない。On the other hand, as shown in FIG. 1 to be described later, if the shaft diameter of the support portion is equal to or larger than the root diameter of the thread groove, additional shaft end machining cannot be performed. In such a case, an extended member (corresponding to the shaft end of the ground screw shaft) is friction-welded to at least one end surface of the screw member having a thread groove formed on the outer peripheral surface over the entire length by rolling. After joining by
A supporting portion (and a component mounting portion) having a desired size and shape is formed on the extended member by machining. It goes without saying that the shaft diameter of the support portion is equal to or larger than the root diameter of the thread groove.

【０００８】次に、この延設部材が摩擦圧接によって接
合された転造ねじ軸の製作工程を略述する。前述の通し
転造によって、所望の長さより長いねじ部材を製作す
る。このねじ部材の端面に、ねじ部材の外径より大径で
且つ所望の長さより長い延設部材の端面を摩擦圧接によ
って接合する。接合後、接合部の周囲に生じたバリを除
去する。バリを除去したねじ部材の外周面を高周波焼入
れ又は浸炭焼入れによって表面硬化した後、焼戻しを行
う。ねじ部材の外周面をバフ仕上げする。その後、機械
加工によって、この延設部材に所望の寸法・形状の支持
部（及び部品取付部）を形成する。なお、 後述の図１（ａ）に示すように、その径がねじ部材の
外径以上の軸部（９）を設けたい場合にも、上述の製作
方法が用いられている。 外周面が焼入れ表面硬化されたねじ部材を延設部材に
接合できない理由は、摩擦圧接の熱影響によって、ねじ
溝面の硬さが低下するとともにリード精度が損なわれる
からである。 ねじ部材と延設部材の長さをそれぞれ所望の長さより
長くする理由は、摩擦圧接によって全体の長さが短くな
るからである。Next, a process of manufacturing a rolled screw shaft in which the extended members are joined by friction welding will be briefly described. By the above-described thread rolling, a screw member longer than a desired length is manufactured. The end surface of the extension member having a diameter larger than the outer diameter of the screw member and longer than a desired length is joined to the end surface of the screw member by friction welding. After joining, burrs generated around the joint are removed. After the outer peripheral surface of the screw member from which burrs are removed is hardened by induction hardening or carburizing quenching, tempering is performed. Buffing the outer peripheral surface of the screw member. Thereafter, a support portion (and a component mounting portion) having a desired size and shape are formed on the extended member by machining. In addition, as shown in FIG. 1A described later, the above-described manufacturing method is also used when it is desired to provide a shaft portion (9) whose diameter is equal to or larger than the outer diameter of the screw member. The reason that the screw member whose outer peripheral surface is hardened and surface-hardened cannot be joined to the extension member is because the thermal effect of friction welding reduces the hardness of the screw groove surface and impairs the lead accuracy. The reason why the length of each of the screw member and the extension member is longer than the desired length is that the entire length is shortened by friction welding.

【０００９】[0009]

【発明が解決しようとする課題】しかし、従来のねじ部
材の端面に延設部材が接合された転造ねじ軸において
は、 （１）上述の製作工程を経る必要があるため、製作コス
トが大幅にアップする。 （２）前述の研削ねじ軸と同様に、高周波焼入れの場
合、ねじ部材の延設部材近傍の焼入れが不完全になるか
ら、ねじ部材の有効長さを所望のナット移動距離より長
くしなければならない（すなわち、転造ねじ軸の全長が
長くなる。）。また、浸炭焼入れの場合、延設部材近傍
までの完全焼入れは可能であるが、延設部材を防炭処理
しなければならない。 （３）焼入れ表面硬化後、ねじ部材の伸縮等に起因して
所望のリード精度を満足しないものがある。リード精度
を満足しない場合、バフ仕上げされたねじ溝を研削又は
ラップ加工しなければならない。 （４）前述の在庫生産された転造ねじ軸を活用できな
い。という問題があった。However, in a conventional rolled screw shaft in which an extension member is joined to the end surface of a conventional screw member, (1) the manufacturing process is required to go through the above-described manufacturing process, and the manufacturing cost is large. Up. (2) As in the case of the above-described grinding screw shaft, in the case of induction hardening, since the hardening of the screw member near the extending member becomes incomplete, the effective length of the screw member must be longer than the desired nut moving distance. (That is, the overall length of the rolled screw shaft becomes longer). In the case of carburizing and quenching, complete quenching up to the vicinity of the extended member is possible, but the extended member must be subjected to a carburizing treatment. (3) After quenching and surface hardening, there is a case where a desired lead accuracy is not satisfied due to expansion and contraction of a screw member or the like. If the lead accuracy is not satisfied, the buffed thread groove must be ground or lapped. (4) The above-mentioned rolled screw shaft produced in stock cannot be used. There was a problem.

【００１０】また、従来の研削ねじ軸においても、前述
の製作工程によって、軸端部にねじ溝の谷径以上の軸径
を有する支持部が形成されたねじ軸、又は軸端部にねじ
部の外径より大径の軸部が形成されたねじ軸を製作する
場合、鋼丸棒（素材）の径寸法が大きくなる。このた
め、材料歩留り及び生産性の低下を招来し、製作コスト
が著しく高くなるという問題があった。なお、支持部の
軸径がねじ溝の谷径以上の転造ねじ軸（延設部材が接合
された転造ねじ軸）又は研削ねじ軸においては、選定し
た転がり軸受に対する肩の高さを確保するため、転造ね
じ軸におけるねじ部材又は研削ねじ軸におけるねじ部と
支持部との間に、後述の図１（ａ）に示すような雄ねじ
部（６）（この雄ねじ部（６）に、止ねじ付ベアリング
ナット（前述の「総合カタログ」A-239頁参照）が螺合
される。）、又は同図（ｂ）に示すようなカラー相当部
（１５）が設けられる。Also, in the conventional grinding screw shaft, a screw shaft having a support portion having a shaft diameter equal to or larger than the root diameter of the screw groove formed at the shaft end portion by the above-described manufacturing process, or a screw portion at the shaft end portion. When manufacturing a screw shaft having a shaft portion having a diameter larger than the outer diameter of the steel rod, the diameter of the steel round bar (raw material) is increased. For this reason, there has been a problem that the material yield and productivity are reduced, and the manufacturing cost is significantly increased. In the case of a rolled screw shaft (rolled screw shaft to which an extension member is joined) or a ground screw shaft in which the shaft diameter of the support portion is equal to or larger than the root diameter of the thread groove, the shoulder height for the selected rolling bearing is secured. Therefore, between the screw member of the rolled screw shaft or the screw portion of the ground screw shaft and the support portion, a male screw portion (6) as shown in FIG. A bearing nut with a set screw (see the above-mentioned “General Catalog”, page A-239) is screwed.) Or a collar equivalent part (15) as shown in FIG.

【００１１】本発明は、従来の技術の有するこのような
問題点に鑑みてなされたものであり、製作コストを従来
のものより廉価にすることができる、ねじ部材の少なく
とも一方の端面又は端部に延設部材が接合されたボール
ねじのねじ軸を提供することを目的としている。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and at least one end face or end of a screw member can be manufactured at a lower cost. It is an object of the present invention to provide a screw shaft of a ball screw to which an extension member is joined.

【００１２】[0012]

【課題を解決するための手段】上記の目的を達成するた
めに、本発明の請求項１に係るボールねじのねじ軸は、
予め外周面にねじ溝が全長に亘って形成されたねじ部材
と、該ねじ部材の少なくとも一方の端面に接合された延
設部材とからなるボールねじのねじ軸であって、前記ね
じ部材と前記延設部材は同一の材質からなり、該延設部
材が接合される前に、前記ねじ部材の外周面が高周波焼
入れ又は浸炭焼入れによって表面硬化されるとともに仕
上げ加工されており、前記ねじ部材の端面に突設された
前記ねじ溝の谷径より小径の突出軸に、前記延設部材の
端面に穿設された円孔を、前記延設部材の端面が前記ね
じ部材の端面に密接するように焼ばめした後、前記延設
部材にねじりを与えて該延設部材の前記ねじ部材に対す
る位相をずらし、該位相をずらすときに生じる摩擦で前
記突出軸と前記円孔のはめあい面及び前記ねじ部材と前
記延設部材の密接する端面同士を焼付かせることによっ
て前記ねじ部材の端面に前記延設部材が接合されている
ことを特徴とする。In order to achieve the above object, a screw shaft of a ball screw according to claim 1 of the present invention comprises:
A screw shaft of a ball screw including a screw member in which a screw groove is formed on the outer peripheral surface over the entire length in advance and an extended member joined to at least one end surface of the screw member, wherein the screw member and the screw member The extension member is made of the same material, and before the extension member is joined, the outer peripheral surface of the screw member is subjected to surface hardening and high-frequency hardening or carburizing quenching and finished, and the end surface of the screw member is formed. A circular hole formed in the end face of the extending member is formed on the projecting shaft having a smaller diameter than the root diameter of the screw groove protruded so that the end face of the extending member comes into close contact with the end face of the screw member. After shrink fitting, the extension member is twisted to shift the phase of the extension member with respect to the screw member, and the fitting surface between the projecting shaft and the circular hole and the screw are formed by friction generated when the phase is shifted. Close contact between the member and the extension member That the extending member to the end face of the screw member by causing the end faces baked stick is characterized in that it is joined.

【００１３】請求項２に係るボールねじのねじ軸は、請
求項１記載のボールねじのねじ軸において、前記突出軸
と前記円孔は、それぞれ、前記ねじ部材及び前記延設部
材の各端面側から互いに対応する小径部と大径部とから
なる段付き形状である構成とする。According to a second aspect of the present invention, in the screw shaft of the ball screw according to the first aspect, the projecting shaft and the circular hole are respectively provided on the end surfaces of the screw member and the extending member. And a stepped shape including a small-diameter portion and a large-diameter portion corresponding to each other.

【００１４】請求項３に係るボールねじのねじ軸は、請
求項１記載のボールねじのねじ軸において、前記突出軸
と前記円孔は、それぞれ、前記ねじ部材及び前記延設部
材の各端面側から互いに対応する大径部と小径の三角ね
じ部とからなる段付き形状である構成とする。According to a third aspect of the present invention, in the screw shaft of the ball screw according to the first aspect, the projecting shaft and the circular hole are respectively formed on the end surfaces of the screw member and the extending member. And a stepped shape composed of a large-diameter portion and a small-diameter triangular screw portion corresponding to each other.

【００１５】また、本発明の請求項４に係るボールねじ
のねじ軸は、予め外周面にねじ溝が全長に亘って形成さ
れたねじ部材と、該ねじ部材の少なくとも一方の端部に
接合された延設部材とからボールねじのねじ軸であっ
て、前記ねじ部材と前記延設部材は同一の材質からな
り、該延設部材が接合される前に、前記ねじ部材の外周
面が高周波焼入れ又は浸炭焼入れによって表面硬化され
るとともに仕上げ加工されており、前記ねじ部材の端部
に、前記延設部材の端面に穿設された円孔を、該円孔の
底面が前記ねじ部材の端面に密接するように焼ばめした
後、前記延設置部材にねじりを与えて該延設部材の前記
ねじ部材に対する位相をずらし、該位相をずらすときに
生じる摩擦で前記ねじ部材の端部と前記円孔のはめあい
面及び密接する前記ねじ部材の端面と前記円孔の底面同
士を焼付かせることによって前記ねじ部材の端部に前記
延設部材が接合されていることを特徴とする。[0015] The screw shaft of the ball screw according to claim 4 of the present invention is joined to a screw member in which a screw groove is formed on the outer peripheral surface over the entire length in advance, and to at least one end of the screw member. A screw shaft of the ball screw from the extending member, wherein the screw member and the extending member are made of the same material, and the outer peripheral surface of the screw member is induction hardened before the extending member is joined. Alternatively, the surface is hardened by carburizing and quenching and finish processing is performed, and a circular hole formed in the end surface of the extending member is formed at the end of the screw member, and the bottom surface of the circular hole is formed at the end surface of the screw member. After shrink fitting so as to be in close contact with each other, the extending member is twisted to shift the phase of the extending member with respect to the screw member, and the end of the screw member and the circle are moved by friction generated when the phase is shifted. The fitting surface of the hole and the close contact It said extending member to an end portion of the screw member by causing adhere baked end face of the member and the bottom ends of the circular hole is characterized in that it is joined.

【００１６】請求項５に係るボールねじのねじ軸は、請
求項４記載のボールねじのねじ軸において、前記円孔に
設けた前記ねじ溝と相補う形状の突条が前記ねじ溝に螺
合されている構成とする。According to a fifth aspect of the present invention, in the screw shaft of the ball screw according to the fourth aspect, a protrusion having a shape complementary to the thread groove provided in the circular hole is screwed into the thread groove. Configuration.

【００１７】本発明の請求項１〜５に係るボールねじの
ねじ軸によれば、 （１）ねじ部材は在庫生産された転造ねじ軸又は研削ね
じ軸を切断したものであるから、製作コストを従来のも
のより廉価にすることができる。 （２）焼ばめ後、はめあい面及び密接面同士を焼付かせ
るようにしたので、ねじ部材と延設部材（機械加工後
は、支持部等からなる延設部材）の接合をより強固にす
ることができる。このため、ねじ軸が駆動手段によって
回転駆動される際、作用するねじりモーメント又は反転
時の衝撃によって、支持部等からなる延設部材に対する
ねじ部材の位相がずれる虞はない。また、本発明の請求
項２，３及び５に係るボールねじのねじ軸によれば、突
出軸と円孔（請求項２，３）、または、ねじ溝と円孔
（請求項５）を係合させるようにしたので、ねじ部材か
ら延設部材（機械加工後は、支持部等からなる延設部
材）が抜脱する虞はない。特に、請求項３に係るボール
ねじのねじ軸によれば、ねじ軸に予張力を付与すること
ができる。According to the screw shaft of the ball screw according to the first to fifth aspects of the present invention, (1) Since the screw member is obtained by cutting a rolled screw shaft or a ground screw shaft that is manufactured in stock, the manufacturing cost is reduced. Can be made less expensive than conventional ones. (2) After the shrink fitting, the fitting surface and the close contact surface are made to seize each other, so that the joining between the screw member and the extending member (after machining, the extending member including the support portion and the like) is further strengthened. be able to. For this reason, when the screw shaft is rotationally driven by the driving means, there is no possibility that the phase of the screw member is shifted with respect to the extended member including the support portion due to the torsional moment acting or the impact at the time of reversal. According to the screw shaft of the ball screw according to claims 2, 3 and 5 of the present invention, the projecting shaft and the circular hole (claims 2 and 3) or the screw groove and the circular hole (claim 5) are related. Since it is made to fit, there is no danger that the extended member (extended member composed of a support portion or the like after machining) will come off from the screw member. In particular, according to the screw shaft of the ball screw according to the third aspect, a pretension can be applied to the screw shaft.

【００１８】[0018]

【発明の実施の形態】以下、図面を参照して本発明の実
施の形態を説明する。なお、 （１）後述のねじ部材は、同様に後述の延設部材が接合
される前に、その外周面にねじ溝が全長に亘って形成さ
れ、且つ、この外周面が高周波焼入れ又は浸炭焼入れに
よって表面硬化されるとともに仕上げ加工をされてい
る。すなわち、ねじ部材は、前述の在庫生産された転造
ねじ軸、又は前述の製作工程に準じて（但し、軸端部は
設けない。）在庫生産された研削ねじ軸を、砥石等によ
って機械加工時の取りしろを残した所望の長さに切断し
たものである。 （２）ねじ部材と延設部材は、同一の材質からなる。材
質を同一にする理由は、後述の線膨張係数が同じ値にな
るという観点もあるが、「同じ材質同士の摩擦では、互
いに溶け合いやすく、焼付きを起こしやすい。」という
性質を利用するためである。すなわち、後述するよう
に、ねじ部材に延設部材を焼ばめ後、延設部材にねじり
を与えて延設部材のねじ部材に対する位相をずらし、こ
の位相をずらすときに生じる摩擦で、はめあい面及び密
接面同士を焼付かせるためである。Embodiments of the present invention will be described below with reference to the drawings. In addition, (1) a screw groove is formed on the outer peripheral surface of the screw member to be described later over the entire length before an extended member to be described later is joined, and the outer peripheral surface is induction hardened or carburized hardened. The surface is hardened and finished. That is, the screw member is formed by machining a rolled screw shaft manufactured in stock as described above or a grounded screw shaft manufactured in accordance with the above-described manufacturing process (however, no shaft end is provided) using a grindstone or the like. It is cut to the desired length leaving a margin for time. (2) The screw member and the extension member are made of the same material. The reason why the materials are the same is that there is a viewpoint that the coefficient of linear expansion described later has the same value, but it is to utilize the property that "the friction between the same materials easily melts together and easily causes seizure". is there. That is, as described later, after the extension member is shrink-fitted to the screw member, the extension member is twisted to shift the phase of the extension member with respect to the screw member, and the friction generated when shifting the phase causes the fitting surface to be fitted. This is to make the close surfaces stick to each other.

【００１９】図１は、本発明におけるボールねじのねじ
軸を示す。同図（ａ）のねじ軸１は、ねじ部材２の両端
面にねじ部材２の外径Ａより大径の延設部材３，７が接
合された後、機械加工によって、延設部材３にねじ溝
（図示せず。）の谷径Ｂより大径の支持部４、ねじ溝の
谷径Ｂより小径の部品取付部５及びねじ部材２の外径Ａ
より大径の雄ねじ部６が形成されるとともに、延設部材
７にねじ溝の谷径Ｂより小径の支持部８及びねじ部材２
の外径Ａと同径の軸部９が形成されたねじ軸である。ま
た、同図（ｂ）のねじ軸１０は、ねじ部材１１の一方の
端部にねじ部材１１の外径Ｐより大径の延設部材１２が
接合された後、機械加工によって、この延設部材１２に
ねじ部材１１の外径Ｐ（ねじ溝（後述の図７（ｂ）参
照）の谷径Ｑ）より大径の支持部１３、部品取付部１４
及びカラー相当部１５が形成されたねじ軸である。な
お、符号２Ａ，１１Ａは、それぞれ、ねじ部材２，１１
のねじ溝を含む外周面を示す。また、同図（ｂ）のねじ
軸１０のような形態は、外径Ｐが４〜１２ｍｍの、いわ
ゆる、ミニチュアボールねじに適用される。FIG. 1 shows a screw shaft of a ball screw according to the present invention. The screw shaft 1 shown in FIG. 1A is formed by joining the extension members 3 and 7 having a larger diameter than the outer diameter A of the screw member 2 to both end surfaces of the screw member 2 and then machining the extension members 3. The support portion 4 having a diameter larger than the root diameter B of the screw groove (not shown), the component mounting portion 5 having a diameter smaller than the root diameter B of the screw groove, and the outer diameter A of the screw member 2.
A male screw portion 6 having a larger diameter is formed, and a support portion 8 and a screw member 2 having a diameter smaller than the root diameter B of the thread groove are formed on the extension member 7.
Is a screw shaft on which a shaft portion 9 having the same diameter as the outer diameter A is formed. The screw shaft 10 shown in FIG. 2B is formed by machining after an extension member 12 having a diameter larger than the outer diameter P of the screw member 11 is joined to one end of the screw member 11. The member 12 has a support portion 13 and a component mounting portion 14 which are larger in diameter than the outer diameter P of the screw member 11 (the root diameter Q of a screw groove (see FIG. 7B described later)).
And a screw shaft on which the collar equivalent portion 15 is formed. Reference numerals 2A and 11A represent screw members 2 and 11 respectively.
3 shows an outer peripheral surface including the screw groove of FIG. Further, a form like the screw shaft 10 in FIG. 3B is applied to a so-called miniature ball screw having an outer diameter P of 4 to 12 mm.

【００２０】次に、図１（ａ）のねじ部材２の端面に延
設部材３を接合する方法（実施の形態）について説明す
る。なお、ねじ部材２の端面に延設部材７を接合する方
法は、延設部材３の場合と同様であるので、その説明は
省略する。また、同図（ｂ）のねじ部材１１の端部に延
設部材１２を接合する方法は後述する。図２（ａ）に示
すように、ねじ部材２には、その端面１７に軸径Ｃ（Ｂ
＞Ｃ）及び軸長Ｌ1の突出軸１６が突設されている。こ
の軸径Ｃと軸長Ｌ1は、突出軸１６と後述の焼ばめされ
る円孔１８の接触面積を大きくする観点から、Ｌ1＝
（１．５〜２．５）＊Ｃ の関係を満足するように形成
されている。また、突出軸１６と端面１７との境界は、
応力集中を緩和する観点から、円弧状に形成されてい
る。さらに、突出軸１６の先端には、円孔１８を焼ばめ
しやすくする観点から、３０〜４５°の面取りが形成さ
れている。なお、突出軸１６の軸径Ｃは、突出軸１６と
支持部４との間の肉厚を考慮しなければならないが、曲
げモーメントに対する強度の観点から、できるだけ大き
くなるように設定されている。Next, a method (embodiment) for joining the extension member 3 to the end face of the screw member 2 in FIG. 1A will be described. The method of joining the extension member 7 to the end face of the screw member 2 is the same as that of the extension member 3, and a description thereof will be omitted. The method of joining the extension member 12 to the end of the screw member 11 in FIG. As shown in FIG. 2A, the screw member 2 has a shaft diameter C (B
> C) and the projecting shaft 16 of the axial length L 1 is projected. The shaft diameter C and axial length L 1, from the viewpoint of increasing the contact area of the circular hole 18 which is shrink-fit below the protrusion shaft 16, L 1 =
It is formed so as to satisfy the relationship of (1.5 to 2.5) * C. The boundary between the protruding shaft 16 and the end face 17 is
It is formed in an arc shape from the viewpoint of reducing stress concentration. Further, a chamfer of 30 to 45 ° is formed at the tip of the protruding shaft 16 from the viewpoint of facilitating shrink fitting of the circular hole 18. The shaft diameter C of the protruding shaft 16 must be set to be as large as possible from the viewpoint of strength against bending moment, although the thickness between the protruding shaft 16 and the support portion 4 must be considered.

【００２１】突出軸１６の形成方法を説明する。ねじ部
材２は、前述したように、在庫生産された転造ねじ軸又
は研削ねじ軸を砥石等によって所定の長さよりＬ3だけ
長く切断したものである（但し、ねじ部材２の一方の端
面にのみ、延設部材３が接合されるものとする。）。そ
して、このねじ部材２の軸端が長さＬ3だけ焼ならしさ
れた後、機械加工によって、この軸端に突出軸１６が形
成される。なお、ねじ部材２の軸線（図示せず。）に対
する突出軸１６の同軸度及び端面１７の直角度を、でき
るだけ小さくすることが好ましい。また、突出軸１６と
端面１７を一回のチャッキングで研削仕上げすることが
好ましい。A method for forming the protruding shaft 16 will be described. The screw member 2, as described above, by grinding or the like rolling screw shaft or grinding screw shaft is inventory produced is obtained by a long cut only L 3 than the predetermined length (however, the one end face of the screw member 2 Only the extension member 3 is joined.) After the shaft end of the screw member 2 is normalizing tempered by a length L 3, by machining, projecting shaft 16 is formed in the shaft end. It is preferable that the coaxiality of the protruding shaft 16 and the perpendicularity of the end face 17 to the axis (not shown) of the screw member 2 be as small as possible. Further, it is preferable that the protruding shaft 16 and the end face 17 are ground by a single chucking.

【００２２】図２（ｂ）に示すように、外径Ｄ（Ａ＜
Ｄ）の延設部材３には、その端面１９に孔径Ｅ及び深さ
Ｌ2の円孔１８が穿設されている。この孔径Ｅは、上述
の突出軸１６の軸径Ｃに対して Ｃ＝Ｅ＋δ（式中、δ
は焼ばめしろ）の関係を満足するように形成されている
（研削又はラップ仕上げが好ましい。）。また、深さＬ
2は、突出軸１６の端面１７に延設部材３の端面１９を
密接させる観点から、突出軸１６の軸長Ｌ1に対して Ｌ
1＜Ｌ2 の関係を満足するように形成されている。さら
に、円孔１８の口元は、突出軸１６に対応した円弧状に
形成されている。なお、後述の他の実施の形態において
も同様であるが、延設部材３の外周面と円孔１８との間
に空気抜け孔（図示せず。）を設けてもよい（焼ばめ
後、空気抜け孔はピンで閉塞される。）。また、円孔１
８の穿設及び端面１９の機械加工に際して、延設部材３
の軸線（図示せず。）に対する円孔１８の同軸度及び端
面１９の直角度を、できるだけ小さくすることが好まし
い。さらに、端面１９を研削仕上げすることが好まし
い。As shown in FIG. 2B, the outer diameter D (A <A
The extension member 3 of (D) has a hole diameter E and a depth at its end face 19.
LTwoAre formed. This hole diameter E is as described above.
C = E + δ (where, δ
Is formed to satisfy the relationship of shrink fit)
(Grinding or lapping is preferred.). Also, the depth L
TwoThe end face 19 of the extension member 3 is attached to the end face 17 of the projecting shaft 16.
From the viewpoint of close contact, the axial length L of the projecting shaft 161For L
1<LTwo Is formed so as to satisfy the above relationship. Further
The mouth of the circular hole 18 has an arc shape corresponding to the protruding shaft 16.
Is formed. In other embodiments described later,
Is the same, but between the outer peripheral surface of the extension member 3 and the circular hole 18.
May be provided with an air vent hole (not shown) (shrink fit)
Later, the air vent is closed with a pin. ). In addition, circular hole 1
8 and machining of the end face 19 during the drilling of the extension member 3
Of the circular hole 18 with respect to the axis (not shown) of
It is preferable to make the squareness of the surface 19 as small as possible.
No. Further, it is preferable to finish the end face 19 by grinding.
No.

【００２３】ここで、上述の焼ばめしろδ、及びこの焼
ばめしろδを得るために必要な突出軸１６と延設部材３
間の温度差ｔの算出式を示す（但し、後述の実施の形態
の説明の都合から一般式で示す。）。今、図３に示すよ
うに、中実軸１００（外半径をＲ1とする。）に外筒１
０２（内半径をＲ2，外半径をＲdとする。）が焼ばめさ
れたとして、はめあい面の半径をＲとする。また、中実
軸１００と外筒１０２の縦弾性係数及びポアソン比が等
しいとする。そうすると、材料力学（例えば、(株)裳華
房発行 鵜戸口英善代表「材料力学下巻」第１１版（昭
47．1．15）第379〜382頁及び第385〜386頁参照）か
ら、はめあい面に生じる焼ばめ圧力ｐ〔Ｎ／ｍｍ2〕、
焼ばめしろδ〔ｍｍ〕、及び焼ばめしろδを得るために
必要な中実軸１００と外筒１０２間の温度差t〔℃〕
は、次式から求められる（但し、Ｒ1≒Ｒ2≒Ｒと近似す
る。）。Here, the above-mentioned shrink-fitting δ, and the protruding shaft 16 and the extending member 3 necessary for obtaining this shrink-fitting δ.
A formula for calculating the temperature difference t between them is shown (however, a general formula is used for convenience of description of the embodiment described later). Now, as shown in FIG. 3, solid shaft 100 (the outer radius is R 1.) In the outer tube 1
02 (the inner radius is R 2 and the outer radius is R d ), the radius of the fitting surface is R. Further, it is assumed that the longitudinal elastic modulus and Poisson's ratio of the solid shaft 100 and the outer cylinder 102 are equal. Then, material mechanics (for example, Hideyoshi Udoguchi, published by Shokabo Co., Ltd., "Material mechanics lower volume" 11th edition (Showa
47.1.15) From pages 379 to 382 and pages 385 to 386), a shrink fit pressure p [N / mm 2 ] generated on the fitting surface,
Shrink fit δ [mm] and temperature difference t [° C.] between the solid shaft 100 and the outer cylinder 102 required to obtain the shrink fit δ
Is obtained from the following equation (however, approximates R 1 ≒ R 2 ≒ R).

【００２４】[0024]

【数１】 (Equation 1)

【００２５】図２に戻って、上式（１），（２）及び
（３）に、それぞれ、Ｒ≒Ｃ／２≒Ｅ／２，及びＲd＝
Ｆ／２（符号Ｆは支持部４の軸径を示す。）を代入すれ
ば、突出軸１６と円孔１８のはめあい面（符号を付さ
ず。）に生じる焼ばめ圧力ｐ、焼ばめしろδ、及び焼ば
めしろδを得るために必要な突出軸１６と延設部材３間
の温度差ｔを求めることができる。次に、具体的な数値
を挙げて例示する。Ｃ＝Ｅ＋δ＝２０ｍｍ＋δ，Ｅ＝２
０ｍｍ，Ｆ＝３０ｍｍとし、ねじ部材２及び延設部材３
の材質を調質炭素鋼Ｓ５５Ｃとする。そして、炭素鋼Ｓ
５５Ｃの許容せん断応力（最大せん断応力）τmax、縦
弾性係数Ｅ、及び線膨張係数αを、それぞれ、τmax＝
９．６×９．８Ｎ／ｍｍ2，Ｅ＝２．１×９．８×１０4
Ｎ／ｍｍ2，及びα＝１．１×１０-5／℃ とすれば、ｐ
≒５．３×９．８Ｎ／ｍｍ2，δ≒１８×１０-3ｍｍ，
及びｔ≒８３℃ になる。なお、 Ｒd＝Ｄ／２としない理由は、機械加工後、支持部４
の半径Ｆ／２がＲdの最小値、すなわち、δの最小値に
なるからである。 ねじ部材２（１条ねじとする。）の諸元を、Ａ＝３２
ｍｍ，Ｂ＝２８．４ｍｍとし、リード及びボール径をそ
れぞれ８ｍｍ及び４．７６３ｍｍとする（図示せ
ず。）。また、Ｌ1＝５０ｍｍ，Ｄ＝３８．５ｍｍとす
る。Returning to FIG. 2, in the above equations (1), (2) and (3), R ≒ C / 2 ≒ E / 2 and R d =
By substituting F / 2 (the symbol F indicates the shaft diameter of the support portion 4), the shrink fit pressure p generated on the fitting surface (not denoted by a sign) between the projecting shaft 16 and the circular hole 18 and the shrinkage The temperature difference t between the protruding shaft 16 and the extension member 3 necessary for obtaining the interference δ and the shrink fit δ can be obtained. Next, specific numerical values will be exemplified. C = E + δ = 20 mm + δ, E = 2
0 mm, F = 30 mm, screw member 2 and extension member 3
Is tempered carbon steel S55C. And carbon steel S
The allowable shear stress (maximum shear stress) τ max of 55C, the modulus of longitudinal elasticity E, and the coefficient of linear expansion α are respectively τ max =
9.6 × 9.8 N / mm 2 , E = 2.1 × 9.8 × 10 4
N / mm 2 and α = 1.1 × 10 −5 / ° C., p
≒ 5.3 × 9.8 N / mm 2 , δ ≒ 18 × 10 -3 mm,
And t ≒ 83 ° C. The reason for not setting R d = D / 2 is that after the machining,
Is the minimum value of R d , that is, the minimum value of δ. The specifications of the screw member 2 (referred to as a single thread) are A = 32
mm, B = 28.4 mm, and the lead and ball diameters are 8 mm and 4.763 mm, respectively (not shown). L 1 = 50 mm and D = 38.5 mm.

【００２６】しかし、突出軸１６の軸径Ｃを２０＋１８
×１０-3ｍｍとし、且つ、突出軸１６と延設部材３間の
温度差ｔを８３℃ とすると、「はめあい」における寸
法許容差は零になるから、突出軸１６に円孔１８を焼ば
めしにくい。そこで、突出軸１６に円孔１８を焼ばめす
る際、円孔１８の孔径Ｅを温度差ｔ＝８３℃ における
膨張寸法２０＋１８×１０-3ｍｍより２０×１０-3ｍｍ
大きくなるようにする。すなわち、前述の式（３）のδ
に（１８＋２０）×１０-3ｍｍを代入して得られる値１
７３℃ を、突出軸１６と延設部材３間の温度差ｔとす
る。そして、図２（ｃ）に示すように、延設部材３の端
面１９がねじ部材２の端面１７に密接するように焼ばめ
する。However, the shaft diameter C of the projecting shaft 16 is set to 20 + 18.
Assuming that the diameter is × 10 −3 mm and the temperature difference t between the protruding shaft 16 and the extension member 3 is 83 ° C., the dimensional tolerance in “fitting” becomes zero. Hard to fit. Therefore, when the protrusion shaft 16 circularly hole 18 baked Bamesuru, expanded dimension a pore size E of the circular hole 18 in the temperature difference t = 83 ℃ 20 + 18 × 10 -3 mm than 20 × 10 -3 mm
Make it bigger. That is, δ in the above equation (3)
Obtained by substituting (18 + 20) × 10 −3 mm for
Let 73 ° C. be the temperature difference t between the protruding shaft 16 and the extension member 3. Then, as shown in FIG. 2C, shrink fitting is performed so that the end face 19 of the extending member 3 is in close contact with the end face 17 of the screw member 2.

【００２７】なお、 室温（２０℃ とする。）に上述の温度差１７３℃ を
加えても２００℃ を越えないので（調質の際の焼戻し
温度以下）、延設部材３の素地硬さ及びミクロ組織に悪
影響を及ぼさないと考えられる。 延設部材３は、例えば、２０＋１７３℃ になるよう
に温度制御された熱風加熱装置（図示せず。）によって
加熱されながら焼ばめされる。このとき、延設部材３の
温度が２０＋１７３℃ に上昇するまで時間を要するの
で、予め延設部材３を所定の温度に加熱しておけば（例
えば、１５０℃ に温度制御された恒温槽内に保温して
おく。）、焼ばめ作業を迅速に行うことができる。 上述の２０×１０-3ｍｍという値は、JIS B 0401（寸
法公差及びはめあい）に規定される「穴の公差域クラ
ス」すきまばめＨ７に準じている。Note that, even if the above-mentioned temperature difference of 173 ° C. is added to room temperature (20 ° C.), the temperature does not exceed 200 ° C. (less than the tempering temperature at the time of refining). It is not expected to adversely affect the microstructure. The extension member 3 is shrink-fitted while being heated by, for example, a hot-air heating device (not shown) whose temperature is controlled to 20 + 173 ° C. At this time, since it takes time until the temperature of the extension member 3 rises to 20 + 173 ° C., it is necessary to heat the extension member 3 to a predetermined temperature in advance (for example, in a thermostat controlled at 150 ° C.). Insulation can be performed quickly.) The value of 20 × 10 −3 mm described above conforms to the “hole tolerance range class” clearance fit H7 specified in JIS B 0401 (Dimensional tolerance and fit).

【００２８】焼ばめ後、延設部材３にねじりを与えて延
設部材３のねじ部材２に対する位相をずらし、この位相
をずらすときに生じる摩擦で突出軸１６と円孔１８のは
めあい面及び密接する端面１７，１９同士を焼付かせる
ことによって、ねじ部材２の端面１７に延設部材３が接
合される。その後、機械加工によって、延設部材３に支
持部４、部品取付部５及び雄ねじ部６が形成される（図
１（ａ）参照）。なお、後述の他の実施の形態において
も同様であるが、延設部材３にねじりを与える手段とし
て、公知のねじり試験機（例えば、共立出版(株)発行
川田雄一、松浦佑次、水野正夫、宮川松男共編「材料試
験」初版第６刷（昭46．7．5）第63〜64頁参照）とほぼ
同様な構造のねじり装置（図示せず。）が用いられる。
但し、このねじり装置は、ねじ部材２の端面１７近傍
（延設部材３近傍）をチャックで把持して、ねじ部材２
にねじりモーメントが作用しない構造になっている。ま
た、延設部材３のできるだけ端面１９近傍（ねじ部材２
近傍）をチャックで把持して、延設部材３がねじりモー
メントによって塑性変形しないようにすることが好まし
い。After the shrink fitting, the extension member 3 is twisted to shift the phase of the extension member 3 with respect to the screw member 2, and the friction generated when the phase is shifted causes the fitting surfaces of the projecting shaft 16 and the circular hole 18 to fit. The extension member 3 is joined to the end surface 17 of the screw member 2 by burning the end surfaces 17 and 19 that are in close contact with each other. Thereafter, the support portion 4, the component mounting portion 5, and the male screw portion 6 are formed on the extension member 3 by machining (see FIG. 1A). The same applies to other embodiments described later, but as a means for imparting torsion to the extension member 3, a known torsion tester (for example, published by Kyoritsu Shuppan Co., Ltd.)
A twisting device (not shown) having a structure similar to that of Yuichi Kawada, Yuji Matsuura, Masao Mizuno, and Matsuo Miyagawa, "Material Testing," First Edition, 6th Printing (Showa 46.7.5), pp. 63-64). Used.
However, this torsion device grips the vicinity of the end face 17 of the screw member 2 (near the extension member 3) with a chuck, and
The structure is such that no torsional moment acts on Further, the extension member 3 is located as close as possible to the end face 19 (the screw member 2).
(Near) is preferably held by a chuck so that the extension member 3 is not plastically deformed by a torsional moment.

【００２９】この実施の形態によれば、ねじ部材２は在
庫生産された転造ねじ軸又は研削ねじ軸を切断したもの
であるから、製作コストを従来のものより廉価にするこ
とができる。また、突出軸１６に円孔１８を、延設部材
３の端面１９がねじ部材２の端面１７に密接するように
焼ばめした後、延設部材３にねじりを与えて延設部材３
のねじ部材２に対する位相をずらし、この位相をずらす
ときに生じる摩擦で突出軸１６と延設部材３のはめあい
面及びねじ部材２と延設部材３の密接する端面１７，１
９同士を焼付かせるようにしたので、ねじ部材２と延設
部材３（機械加工後は、支持部４、部品取付部５及び雄
ねじ部６からなる延設部材）の接合をより強固にするこ
とができる。このため、図１（ａ）のねじ軸１が駆動手
段（図示せず。）によって回転駆動される際、作用する
ねじりモーメント又は反転時の衝撃によって、支持部
４、部品取付部５及び雄ねじ部６からなる延設部材に対
するねじ部材２の位相、すなわち、円孔１８に対する突
出軸１６の位相がずれる虞はない。According to this embodiment, since the screw member 2 is obtained by cutting a rolled screw shaft or a ground screw shaft that is manufactured in stock, the manufacturing cost can be made lower than the conventional one. Also, after a circular hole 18 is fitted in the projecting shaft 16 so that the end face 19 of the extension member 3 is in close contact with the end face 17 of the screw member 2, the extension member 3 is twisted to give a twist.
Is shifted with respect to the screw member 2, and the frictional surface generated when the phase is shifted causes the fitting surface between the protruding shaft 16 and the extended member 3 and the end surfaces 17 and 1 where the screw member 2 and the extended member 3 come into close contact with each other.
9 are made to stick to each other, so that the joint between the screw member 2 and the extension member 3 (after machining, the extension member composed of the support portion 4, the component mounting portion 5, and the male screw portion 6) is further strengthened. Can be. For this reason, when the screw shaft 1 in FIG. 1A is rotationally driven by a driving means (not shown), the supporting portion 4, the component mounting portion 5, and the male screw portion are caused by a torsional moment acting or an impact at the time of reversal. There is no possibility that the phase of the screw member 2 with respect to the extending member made of 6, that is, the phase of the protruding shaft 16 with respect to the circular hole 18 is shifted.

【００３０】図４は、本発明の第２の実施の形態を示
す。この第２の実施の形態は、上述の第１の実施の形態
の変形態様である。なお、第１の実施の形態と同一又は
相当部分には同一の符号を付して、その説明は省略す
る。同図（ａ）に示すように、ねじ部材２の端面１７に
突設された軸長Ｌ1の突出軸１６は、端面１７側から、
軸径Ｃ（Ｂ＞Ｃ）及び軸長Ｌ4の小径軸部１６Ａと、軸
径Ｇ（Ｂ＞Ｇ＞Ｃ）及び軸長Ｌ5の大径軸部１６Ｂとか
らなる段付き形状とされている。また、同図（ｂ）に示
すように、延設部材３の端面１９に穿設された深さＬ2
の円孔１８は、突出軸１６と同様に、端面１９側から、
孔径Ｅ及び深さＬ6の小径孔部１８Ａと、孔径Ｈ（Ｅ＜
Ｈ）及び深さＬ7の大径孔部１８Ｂとからなる段付き形
状とされている。この小径孔部１８Ａ及び大径孔部１８
Ｂは、それぞれ、小径軸部１６Ａ及び大径軸部１６Ｂに
対応している。さらに、突出軸１６に円孔１８を焼ばめ
する際、ねじ部材２の端面１７に延設部材３の端面１９
を密接させる観点から、軸長Ｌ4と深さＬ6及び軸長Ｌ5
と深さＬ7は、それぞれ、Ｌ4＞Ｌ6及びＬ5＜Ｌ7の関係
を満足するように形成されている。なお、第１の実施の
形態と同様に、小径軸部１６Ａと端面１７との境界は円
弧状に形成されるとともに、小径孔部１８Ａの口元は小
径軸部１６Ａに対応した円弧状に形成されている。ま
た、大径軸部１６Ｂの先端には、３０〜４５°の面取り
が形成されている。FIG. 4 shows a second embodiment of the present invention. This second embodiment is a modification of the above-described first embodiment. The same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 6 (a), the protruding shaft 16 of the axial length L 1 which is projected from the end face 17 of the screw member 2 from the end face 17 side,
A small-diameter shaft portion 16A of the shaft diameter C (B> C) and axial length L 4, is a shaft diameter G (B>G> C), and a stepped shape comprising a large diameter portion 16B of the axial length L 5 I have. Further, as shown in FIG. 3B, a depth L 2 formed in the end face 19 of the extension member 3 is formed.
The circular hole 18 is, like the protruding shaft 16, formed from the end face 19 side.
A small-diameter hole portion 18A having a pore size of E and depth L 6, pore diameter H (E <
There is a stepped shape comprising a large-diameter hole portion 18B of H) and depth L 7. The small-diameter hole 18A and the large-diameter hole 18
B corresponds to the small-diameter shaft portion 16A and the large-diameter shaft portion 16B, respectively. Further, when shrink-fitting the circular hole 18 to the projecting shaft 16, the end face 17 of the extension member 3 is attached to the end face 17 of the screw member 2.
From the viewpoint of making the shaft close to each other, the shaft length L 4 , the depth L 6 and the shaft length L 5
DOO depth L 7 are each formed so as to satisfy the relationship of L 4> L 6 and L 5 <L 7. Note that, similarly to the first embodiment, the boundary between the small diameter shaft portion 16A and the end face 17 is formed in an arc shape, and the mouth of the small diameter hole portion 18A is formed in an arc shape corresponding to the small diameter shaft portion 16A. ing. In addition, a chamfer of 30 to 45 ° is formed at the tip of the large-diameter shaft portion 16B.

【００３１】次に、第１の実施の形態と同様に具体的な
数値を挙げて、小径軸部１６Ａと小径孔部１８Ａ、及び
大径軸部１６Ｂと大径孔部１８Ｂのそれぞれのはめあい
面（符号を付さず。）に生じる焼ばめ圧力ｐ、焼ばめし
ろδ、及び焼ばめしろδを得るために必要な突出軸１６
と延設部材３間の温度差ｔを例示する。Ｃ＝Ｅ＋δ＝２
０ｍｍ＋δ，Ｇ＝Ｃ＋２０×１０-3ｍｍ，Ｅ＝２０ｍ
ｍ，Ｈ＝Ｅ＋２０×１０-3ｍｍ，Ｆ＝３０ｍｍとし、ね
じ部材２及び延設部材３の材質を調質炭素鋼Ｓ５５Ｃと
する。そして、炭素鋼Ｓ５５Ｃの許容せん断応力
τmax、縦弾性係数Ｅ及び線膨張係数αをそれぞれ第１
の実施の形態における値とすれば、前述の式（１），
（２）及び（３）から、ｐ≒５．３×９．８Ｎ／ｍ
ｍ2，δ≒１８×１０-3ｍｍ，及びｔ≒８３℃ になる。
なお、 ねじ部材２（１条ねじとする。）の諸元を、第１の実
施の形態と同様に、Ａ＝３２ｍｍ，Ｂ＝２８．４ｍｍと
し、リード及びボール径をそれぞれ８ｍｍ及び４．７６
３ｍｍとする（図示せず。）。また、Ｌ1＝５０ｍｍ，
Ｄ＝３８．５ｍｍとする。 上述の条件では、小径軸部１６Ａと小径孔部１８Ａの
はめあい面、及び大径軸部１６Ｂと大径孔部１８Ｂのは
めあい面におけるｐ，δ及びｔは、ほぼ同じ値になる。Next, as in the first embodiment, specific fitting values are given to fit surfaces of the small-diameter shaft portion 16A and the small-diameter hole portion 18A, and the large-diameter shaft portion 16B and the large-diameter hole portion 18B. (No symbol is attached.) Shrink fit pressure p, shrink fit δ, and projecting shaft 16 necessary for obtaining shrink fit δ
The temperature difference t between the extension member 3 and the extension member 3 is exemplified. C = E + δ = 2
0 mm + δ, G = C + 20 × 10 −3 mm, E = 20 m
m, H = E + 20 × 10 −3 mm, F = 30 mm, and the material of the screw member 2 and the extension member 3 is tempered carbon steel S55C. Then, the allowable shear stress τ max , the modulus of longitudinal elasticity E and the coefficient of linear expansion α of the carbon steel
Assuming that the values in the embodiment are the above-mentioned expressions (1) and
From (2) and (3), p ≒ 5.3 × 9.8 N / m
m 2 , δ ≒ 18 × 10 −3 mm, and t ≒ 83 ° C.
The specifications of the screw member 2 (referred to as a single thread) are A = 32 mm, B = 28.4 mm, and the lead and ball diameters are 8 mm and 4.76, respectively, as in the first embodiment.
3 mm (not shown). Also, L 1 = 50 mm,
D = 38.5 mm. Under the above conditions, p, δ, and t on the fitting surface between the small diameter shaft portion 16A and the small diameter hole portion 18A and the fitting surface between the large diameter shaft portion 16B and the large diameter hole portion 18B have substantially the same value.

【００３２】しかし、突出軸１６と延設部材３間の温度
差ｔを８３℃ とした場合、軸径Ｇは（２０＋１８×１
０-3）＋２０×１０-3ｍｍであるのに対して、孔径Ｅの
膨張寸法は２０＋１８×１０-3ｍｍであるから、大径軸
部１６Ｂを小径孔部１８Ａに嵌入できない。そこで、突
出軸１６に円孔１８を焼ばめする際、孔径Ｅの膨張寸法
が軸径Ｇと同じ値になる１７３℃ を、突出軸１６と延
設部材３間の温度差ｔとする。そして、図４（ｃ）に示
すように、延設部材３の端面１９がねじ部材２の端面１
７に密接するように焼ばめする。なお、 前述の条件では、Ｇ＞Ｃ＋２０×１０-3ｍｍ，及びＨ
＞Ｅ＋２０×１０-3ｍｍとすると、室温（２０℃ とす
る。）に温度差ｔを加えた値が２００℃ を越えるから
好ましくない。 温度差ｔを１７３℃ にした場合、軸径Ｇと孔径Ｅの
「はめあい」における寸法許容差は零になる。このた
め、延設部材３の反接合側の端面（図示せず。）をプレ
ス等によって押圧して、突出軸１６に円孔１８を焼ばめ
する。However, when the temperature difference t between the projecting shaft 16 and the extension member 3 is 83 ° C., the shaft diameter G is (20 + 18 × 1).
0 −3 ) + 20 × 10 −3 mm, whereas the expansion dimension of the hole diameter E is 20 + 18 × 10 −3 mm, so that the large-diameter shaft portion 16B cannot be fitted into the small-diameter hole portion 18A. Therefore, when shrink-fitting the circular hole 18 in the projecting shaft 16, 173 ° C. at which the expansion dimension of the hole diameter E becomes the same value as the shaft diameter G is defined as the temperature difference t between the projecting shaft 16 and the extending member 3. Then, as shown in FIG. 4C, the end face 19 of the extending member 3 is
Shrink-fit so that it is close to 7. Note that under the above conditions, G> C + 20 × 10 −3 mm and H
If> E + 20 × 10 −3 mm, the value obtained by adding the temperature difference t to room temperature (20 ° C.) exceeds 200 ° C., which is not preferable. When the temperature difference t is 173 ° C., the dimensional tolerance in the “fit” between the shaft diameter G and the hole diameter E becomes zero. For this reason, the end surface (not shown) of the extension member 3 on the non-joining side is pressed by a press or the like, and the circular hole 18 is shrink-fitted on the protruding shaft 16.

【００３３】焼ばめ後、第１の実施の形態と同様に、延
設部材３にねじりを与えて延設部材３のねじ部材２に対
する位相をずらし、この位相をずらすときに生じる摩擦
で突出軸１６と円孔１８のはめあい面（小径軸部１６Ａ
と小径孔部１８Ａ、及び大径軸部１６Ｂと大径孔部１８
Ｂのそれぞれのはめあい面）、並びに、密接する端面１
７，１９同士を焼付かせることによって、ねじ部材２の
端面１７に延設部材３が接合される。その後、機械加工
によって、延設部材３に支持部４、部品取付部５及び雄
ねじ部６が形成される（図１（ａ）参照）。After the shrink fitting, similarly to the first embodiment, the extension member 3 is twisted to shift the phase of the extension member 3 with respect to the screw member 2, and the projection occurs due to the friction generated when the phase is shifted. The fitting surface between the shaft 16 and the circular hole 18 (small diameter shaft portion 16A)
And small-diameter hole 18A, and large-diameter shaft 16B and large-diameter hole 18
B) and the end face 1 which is in close contact
The extension member 3 is joined to the end face 17 of the screw member 2 by burning the members 7 and 19 together. Thereafter, the support portion 4, the component mounting portion 5, and the male screw portion 6 are formed on the extension member 3 by machining (see FIG. 1A).

【００３４】この第２の実施の形態によれば、その軸方
向の位置が万一ずれたとしても、小径軸部１６Ａと大径
軸部１６Ｂ間の段差（符号を付さず。）が小径孔部１８
Ａと大径孔部１８Ｂ間の段差（符号を付さず。）に係合
するようになっているから、ねじ部材２から延設部材３
（機械加工後は、支持部４、部品取付部５及び雄ねじ部
６からなる延設部材）が抜脱する虞はない。その他の作
用は第１の実施の形態と同様であるので、その説明は省
略する。According to the second embodiment, even if the position in the axial direction is deviated, the step between the small-diameter shaft portion 16A and the large-diameter shaft portion 16B (without reference numeral) is reduced in diameter. Hole 18
A and the large-diameter hole portion 18B are engaged with a step (not denoted by a reference numeral).
(After machining, there is no possibility that the extended member including the support portion 4, the component mounting portion 5, and the male screw portion 6) will come off. Other operations are the same as those of the first embodiment, and the description thereof is omitted.

【００３５】図５は、本発明の第３の実施の形態を示
す。この第３の実施の形態も、前述の第１の実施の形態
の変形態様である。なお、上述の第２の実施の形態と同
様に、第１の実施の形態と同一又は相当部分には同一の
符号を付して、その説明は省略する。同図（ａ）に示す
ように、ねじ部材２の端面１７に突設された軸長Ｌ1の
突出軸１６は、端面１７側から、軸径Ｃ（Ｂ＞Ｃ）及び
軸長Ｌ8の大径軸部１６Ｃと、外径Ｉ（Ｃ＞Ｉ）及びね
じ長Ｌ9の小径の三角雄ねじ部１６Ｄとからなる段付き
形状とされている。また、同図（ｂ）に示すように、延
設部材３の端面１９に穿設された深さＬ2の円孔１８
は、突出軸１６と同様に、端面１９側から、孔径Ｅ及び
深さＬ10の大径孔部１８Ｃと、谷径Ｊ（Ｅ＞Ｊ）及びね
じ深さＬ11の小径の三角雌ねじ部１８Ｄとからなる段付
き形状とされている。この大径孔部１８Ｃ及び小径の三
角雌ねじ部１８Ｄは、それぞれ、大径軸部１６Ｃ及び小
径の三角雄ねじ部１６Ｄに対応している。さらに、突出
軸１６に円孔１８を焼ばめする際、ねじ部材２の端面１
７に延設部材３の端面１９を密接させる観点から、軸長
Ｌ8と深さＬ10、及びねじ長Ｌ9とねじ深さＬ11は、それ
ぞれ、Ｌ8＜Ｌ10及びＬ9＜Ｌ11の関係を満足するように
形成されている。なお、第１及び第２の実施の形態と同
様に、大径軸部１６Ｃと端面１７との境界は円弧状に形
成されるとともに、大径孔部１８Ｃの口元は大径軸部１
６Ｃに対応した円弧状に形成されている。FIG. 5 shows a third embodiment of the present invention. This third embodiment is also a modification of the above-described first embodiment. Note that, like the above-described second embodiment, the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 6 (a), the protruding shaft 16 of the axial length L 1 which is projected from the end face 17 of the screw member 2 from the end face 17 side, the shaft diameter C (B> C) and the axial length L 8 a large-diameter shaft portion 16C, which is the outer diameter I (C> I) and a stepped shape comprising a triangular external thread portion 16D of smaller diameter of the screw length L 9. Further, as shown in FIG. 2B, a circular hole 18 having a depth L 2 formed in the end face 19 of the extension member 3.
, Like the protrusion shaft 16, from the end face 19 side, a large-diameter hole portion 18C having a pore size of E and depth L 10, root diameter J (E> J) and the triangular internal thread portion 18D of the small diameter thread depth L 11 And a stepped shape. The large-diameter hole portion 18C and the small-diameter triangular female screw portion 18D correspond to the large-diameter shaft portion 16C and the small-diameter triangular male screw portion 16D, respectively. Further, when shrink-fitting the circular hole 18 to the projecting shaft 16, the end surface 1 of the screw member 2
The end face 19 of the extending member 3 from the viewpoint of close to 7, the axial length L 8 and depth L 10, and a screw length L 9 and thread depth L 11, respectively, L 8 <L 10 and L 9 <L It is formed to satisfy 11 relationships. As in the first and second embodiments, the boundary between the large-diameter shaft portion 16C and the end face 17 is formed in an arc shape, and the mouth of the large-diameter hole portion 18C is formed in the large-diameter shaft portion 1.
It is formed in an arc shape corresponding to 6C.

【００３６】次に、第１の実施の形態において例示した
数値を援用して、この第３の実施の形態における焼ばめ
仕様を説明する。Ｃ＝Ｅ＋δ＝２０＋１８×１０-3ｍ
ｍ，Ｅ＝２０ｍｍ，Ｆ＝３０ｍｍ，とし、ねじ部材２及
び延設部材３の材質を調質炭素鋼Ｓ５５Ｃとする。ま
た、三角雄ねじ部１６Ｄ及び三角雌ねじ部１８Ｄを、有
効径が１６．３７６ｍｍのメートル細目ねじＭ１８×
１．５とする。但し、三角雄ねじ部１６Ｄの有効径は、
後述の計算値から、１６．３７６ｍｍ＋δ´＝１６．３
７６＋１５×１０-3ｍｍとする（Ｉ＞Ｊ）。さらに、前
述の「はめあい」の観点から、突出軸１６に円孔１８を
焼ばめする際、ねじ部材２と延設部材３間の温度差ｔを
１７３℃ とする。そして、図４（ｃ）に示すように、
三角雌ねじ部１８Ｄを三角雄ねじ部１６Ｄに手動で螺合
させながら、延設部材３の端面１９が突出軸１６の端面
１７に密接するように焼ばめする。Next, the shrink fit specification in the third embodiment will be described with reference to the numerical values exemplified in the first embodiment. C = E + δ = 20 + 18 × 10 −3 m
m, E = 20 mm, F = 30 mm, and the material of the screw member 2 and the extension member 3 is tempered carbon steel S55C. In addition, the triangular male screw portion 16D and the triangular female screw portion 18D are replaced with a metric fine screw M18 × 16.376 mm in effective diameter.
1.5. However, the effective diameter of the triangular male screw part 16D is
From a calculated value described later, 16.376 mm + δ ′ = 16.3
76 + 15 × 10 −3 mm (I> J). Further, from the viewpoint of the aforementioned “fitting”, when shrinking the circular hole 18 into the protruding shaft 16, the temperature difference t between the screw member 2 and the extension member 3 is set to 173 ° C. Then, as shown in FIG.
While manually screwing the triangular female screw portion 18D into the triangular male screw portion 16D, shrink-fitting is performed so that the end face 19 of the extension member 3 is in close contact with the end face 17 of the protruding shaft 16.

【００３７】なお、 ねじ部材２（１条ねじとする。）の諸元を、第１の実
施の形態と同様に、Ａ＝３２ｍｍ，Ｂ＝２８．４ｍｍと
し、リード及びボール径をそれぞれ８ｍｍ及び４．７６
３ｍｍとする（図示せず。）。また，Ｌ1＝５０ｍｍ，
Ｄ＝３８．５ｍｍとする。 三角雄ねじ部１６Ｄ及び三角雌ねじ部１８Ｄをメート
ル細目ねじとする理由は、メートル並目ねじより引張強
さが大きいためである。 三角雄ねじ部１６Ｄと三角雌ねじ部１８Ｄの螺接面に
生じる焼ばめ圧力ｐ´、焼ばめしろδ´、及び温度差ｔ
´は、前述の式（１），（２）及び（３）から（但し、
Ｒ＝１６．３７６ｍｍ／２，Ｒd＝３０ｍｍ／２とす
る。）、それぞれ、ｐ´≒６．７×９．８Ｎ／ｍｍ2，
δ´≒１５×１０-3ｍｍ，及びｔ´≒８３℃ になる。The specifications of the screw member 2 (referred to as a single thread) are A = 32 mm, B = 28.4 mm, the lead and ball diameters are 8 mm and 8 mm, respectively, as in the first embodiment. 4.76
3 mm (not shown). Also, L 1 = 50 mm,
D = 38.5 mm. The reason why the triangular male screw portion 16D and the triangular female screw portion 18D are metric fine threads is that the tensile strength is larger than that of the metric coarse threads. Shrink fit pressure p ′, shrink fit δ ′, and temperature difference t generated on the screw contact surface of triangular male screw portion 16D and triangular female screw portion 18D
′ Is obtained from the above equations (1), (2) and (3) (where
R is set to 16.376 mm / 2 and R d is set to 30 mm / 2. ), P ′ ≒ 6.7 × 9.8 N / mm 2 ,
δ ′ ≒ 15 × 10 −3 mm and t ′ ≒ 83 ° C.

【００３８】焼ばめ後、螺合する三角ねじ部１６Ｄ，１
８Ｄをねじ込む方向のねじりを延設部材３に与えて延設
部材３のねじ部材２に対する位相をずらし、この位相を
ずらすときに生じる摩擦で大径軸部１６Ｃと大径孔部１
８Ｃのはめあい面（符号を付さず。）、三角ねじ部１６
Ｄ，１８Ｄの螺接面、及び密接する端面１７，１９同士
を焼付かせることによって、ねじ部材２の端面１７に延
設部材３が接合される。その後、機械加工によって、延
設部材３に支持部４、部品取付部５及び雄ねじ部６が形
成される（図１（ａ）参照）。After the shrink fitting, the triangular screw portions 16D, 1 to be screwed together.
8D is applied to the extension member 3 to shift the phase of the extension member 3 with respect to the screw member 2, and the large-diameter shaft portion 16 </ b> C and the large-diameter hole portion 1 are caused by friction generated when the phase is shifted.
8C fitting surface (not numbered), triangular thread 16
The extension member 3 is joined to the end surface 17 of the screw member 2 by baking the screw contact surfaces of D and 18D and the close end surfaces 17 and 19 with each other. Thereafter, the support portion 4, the component mounting portion 5, and the male screw portion 6 are formed on the extension member 3 by machining (see FIG. 1A).

【００３９】この第３の実施の形態によれば、三角ねじ
部１６Ｄ，１８Ｄが螺合しているから、前述の第２の実
施の形態と同様に、ねじ部材２から延設部材３（機械加
工後は、支持部４、部品取付部５及び雄ねじ部６からな
る延設部材）が抜脱する虞はない。また、図１（ａ）に
示す延設部材７にも第３の実施の形態を適用すれば、ね
じ軸１に予張力を付与することができる。その他の作用
は第１の実施の形態と同様であるので、その説明は省略
する。According to the third embodiment, since the triangular screw portions 16D and 18D are screwed, similarly to the second embodiment, the extension member 3 After the processing, there is no possibility that the extended member including the support portion 4, the component mounting portion 5, and the male screw portion 6 will come off. Further, if the third embodiment is applied to the extending member 7 shown in FIG. 1A, it is possible to apply a pretension to the screw shaft 1. Other operations are the same as those of the first embodiment, and the description thereof is omitted.

【００４０】上述の第１、第２及び第３の実施の形態で
は、ねじ部材２の端面１７に突設された突出軸１６に、
延設部材３の端面１９に穿設された円孔１８を焼ばめし
た後、突出軸１６と円孔１８のはめあい面及び密接する
端面１７，１９同士を焼付かせることによって、ねじ部
材２の端面１７に延設部材３（機械加工後は、支持部
４、部品取付部５及び雄ねじ部６からなる延設部材）が
接合されたボールねじのねじ軸１を説示した（図１
（ａ）参照）。しかし、同図（ｂ）に示すねじ軸１０の
ように、ねじ部材１１の外径Ｐが４〜１２ｍｍの、いわ
ゆる、ミニチュアボールねじのねじ軸では、強度上の問
題があって、ねじ部材１１の端面１１Ｃ（後述の図６
（ａ）参照）に上述のような突出軸を突設させることは
できない。後述の第４及び第５の実施の形態は、このよ
うな場合に適用される。In the first, second and third embodiments, the projecting shaft 16 projecting from the end face 17 of the screw member 2 is
After shrink-fitting the circular hole 18 formed in the end face 19 of the extension member 3, the fitting surface of the protruding shaft 16 and the circular hole 18 and the closely contacting end faces 17 and 19 are seized to form the screw member 2. The screw shaft 1 of the ball screw in which the extension member 3 (extension member including the support portion 4, the component mounting portion 5, and the male screw portion 6 after machining) is joined to the end face 17 is illustrated (FIG. 1).
(A)). However, a screw shaft of a so-called miniature ball screw in which the outer diameter P of the screw member 11 is 4 to 12 mm, such as a screw shaft 10 shown in FIG. The end face 11C of FIG.
(See (a)), it is not possible to protrude the above-mentioned projecting shaft. The fourth and fifth embodiments described below are applied to such a case.

【００４１】図６は、本発明の第４の実施の形態を示
す。同図（ａ）のねじ部材１１は、前述したように、在
庫生産された転造ねじ軸又は研削ねじ軸を砥石等によっ
て端面加工時の取りしろを残した所望の長さに切断した
ものである。そして、このねじ部材１１は、その両端面
（一方の端面１１Ｃのみ図示する。）が機械加工（研削
仕上げが好ましい。）されて、所定の長さになってい
る。なお、 ねじ部材１１が転造ねじ軸からなる場合、ねじ部材１
１の端部１１Ｂの外径、すなわち、端面１１Ｃから長さ
Ｌ12の範囲の外径は、研削加工によって寸法Ｓ（Ｐ＞
Ｓ）に仕上げられている。 ねじ部材１１が研削ねじ軸からなる場合、予めその外
径が所定の寸法精度に研削仕上げされているので（Ｐ＝
Ｓ）、端部１１Ｂを再加工する必要はない。 端面１１Ｃの機械加工に際して、ねじ部材１１の軸線
（図示せず。）に対する端面１１Ｃの直角度を、できる
だけ小さくすることが好ましい。FIG. 6 shows a fourth embodiment of the present invention. The screw member 11 shown in FIG. 1A is obtained by cutting a rolled screw shaft or a ground screw shaft, which is manufactured in stock, to a desired length with a margin at the time of processing the end face by using a grindstone or the like, as described above. is there. The screw member 11 has both ends (only one end surface 11C is shown) machined (preferably ground) to have a predetermined length. When the screw member 11 is formed by a rolled screw shaft, the screw member 1
The outer diameter of the first end portion 11B, i.e., the outer diameter of the range of the length L 12 from the end face 11C, the size by grinding S (P>
S). When the screw member 11 is formed of a ground screw shaft, its outer diameter is previously ground to a predetermined dimensional accuracy (P =
S), there is no need to rework the end 11B. When machining the end face 11C, it is preferable to make the perpendicularity of the end face 11C to the axis (not shown) of the screw member 11 as small as possible.

【００４２】図６（ｂ）に示すように、外径Ｕ（Ｐ＜
Ｕ）の延設部材１２には、その端面２１に孔径Ｔ及び深
さＬ13の円孔２０が穿設されている。この孔径Ｔは、上
述の端部１１Ｂの外径Ｓに対して Ｔ＝Ｓ−δ（式中、
δは焼ばめしろ）の関係を満足するように形成されてい
る（研削又はラップ仕上げが好ましい。）。また、深さ
Ｌ13は、ねじ部材１１の端面１１Ｃに底面２２を密接さ
せる観点から、端部１１Ｂの長さＬ12に対して Ｌ12＞
Ｌ13 の関係を満足するように形成されている。なお、
円孔２０の穿設に際して、延設部材１２の軸線（図示せ
ず。）に対する円孔２０の同軸度及び底面２２の直角度
を、できるだけ小さくすることが好ましい。また、底面
２２を研削又はラップ仕上げすることが好ましい。As shown in FIG. 6B, the outer diameter U (P <
The extending member 12 of the U), circular holes 20 having a pore size of T and depth L 13 is bored in the end face 21. This hole diameter T is given by T = S−δ (where,
is formed so as to satisfy the relationship (shrink fit) (grinding or lapping is preferable). The depth L 13, from the viewpoint of close contact with the bottom surface 22 on the end face 11C of the screw member 11, L 12 with respect to the length L 12 of the end portion 11B>
It is formed so as to satisfy the relationship of L 13. In addition,
When the circular hole 20 is formed, it is preferable to minimize the coaxiality of the circular hole 20 with respect to the axis (not shown) of the extending member 12 and the perpendicularity of the bottom surface 22 as much as possible. Further, it is preferable that the bottom surface 22 is ground or lapped.

【００４３】次に、前述の第１、第２及び第３の実施の
形態と同様に具体的な数値を挙げて、端部１１Ｂと円孔
２０のはめあい面（符号を付さず。）に生じる焼ばめ圧
力ｐ、焼ばめしろδ、及び焼ばめしろδを得るために必
要なねじ部材１１と延設部材１２間の温度差ｔを例示す
る。Ｓ＝４．０ｍｍ，Ｔ＝Ｓ−δ＝４．０ｍｍ−δ，Ｖ
＝９．５ｍｍ（符号Ｖはカラー相当部１５の外径を示
す。）とし、ねじ部材１１及び延設部材１２の材質を調
質炭素鋼Ｓ５５Ｃとする。そして、炭素鋼Ｓ５５Ｃの許
容せん断応力τmax、縦弾性係数Ｅ、及び線膨張係数α
を、それぞれ、τmax＝９．６×９．８Ｎ／ｍｍ2，Ｅ＝
２．１×９．８×１０4Ｎ／ｍｍ2，及びα＝１．１×１
０-5／℃ とすれば、前述の式（１），（２）及び
（３）から、ｐ≒７．９×９．８Ｎ／ｍｍ2，δ≒４×
１０-3ｍｍ，及びｔ≒８３℃ になる。なお、ねじ部材
１１（１条ねじとする。）の諸元を、Ｐ＝Ｓ＝４．０ｍ
ｍ（ねじ部材１１が研削ねじ軸の場合），Ｑ＝３．３ｍ
ｍとし、リード及びボール径をそれぞれ１ｍｍ及び０．
８ｍｍとする（図示せず。）。また、Ｌ13＝７ｍｍとす
る。Next, as in the first, second, and third embodiments, specific numerical values are given to the fitting surfaces (not denoted by reference numerals) of the end portion 11B and the circular hole 20. The resulting shrink fit pressure p, shrink fit δ, and temperature difference t between the screw member 11 and the extension member 12 required to obtain the shrink fit δ are illustrated. S = 4.0 mm, T = S−δ = 4.0 mm−δ, V
= 9.5 mm (symbol V indicates the outer diameter of the collar equivalent portion 15), and the material of the screw member 11 and the extension member 12 is tempered carbon steel S55C. The allowable shear stress τ max , the longitudinal elastic modulus E, and the linear expansion coefficient α of the carbon steel S55C
Τ max = 9.6 × 9.8 N / mm 2 and E =
2.1 × 9.8 × 10 4 N / mm 2 and α = 1.1 × 1
If 0 −5 / ° C., p ≒ 7.9 × 9.8 N / mm 2 , δ ≒ 4 × from the above equations (1), (2) and (3).
10 −3 mm and t ≒ 83 ° C. The specifications of the screw member 11 (referred to as a single thread) are P = S = 4.0 m.
m (when the screw member 11 is a ground screw shaft), Q = 3.3 m
m, and the lead and ball diameters are 1 mm and 0.1 mm, respectively.
8 mm (not shown). L 13 = 7 mm.

【００４４】しかし、端部１１Ｂの外径Ｓを Ｓ＝４．
０ｍｍとし、且つ、ねじ部材１１と延設部材１２間の温
度差ｔを８３℃ とすると、「はめあい」における寸法
許容差が零になるから、端部１１Ｂに円孔２０を焼ばめ
しにくい。そこで、端部１１Ｂを円孔２０に焼ばめする
際、円孔２０の孔径Ｔが温度差ｔ＝８３℃ における膨
張寸法４．０ｍｍより４×１０-3ｍｍ大きくなる温度、
すなわち、室温（２０℃ とする。）を加えた値が２０
０℃ になる１８０℃ を、ねじ部材１１と延設部材１２
間の温度差ｔとする。そして、図６（ｃ）に示すよう
に、円孔２０の底面２２がねじ部材１１の端面１１Ｃに
密接するように焼ばめする。However, when the outer diameter S of the end 11B is S = 4.
If 0 mm and the temperature difference t between the screw member 11 and the extension member 12 is 83 ° C., the dimensional tolerance in “fitting” becomes zero, so that it is difficult to fit the circular hole 20 in the end 11B. Therefore, when shrink-fitting the end portion 11B into the circular hole 20, the temperature at which the hole diameter T of the circular hole 20 becomes 4 × 10 −3 mm larger than the expansion dimension 4.0 mm at the temperature difference t = 83 ° C.
That is, the value obtained by adding the room temperature (20 ° C.) is 20.
180 ° C., which becomes 0 ° C., is applied to the screw member 11 and the extension member 12
And a temperature difference t between them. Then, as shown in FIG. 6C, shrink fitting is performed so that the bottom surface 22 of the circular hole 20 is in close contact with the end surface 11 </ b> C of the screw member 11.

【００４５】焼ばめ後、延設部材１２にねじりを与えて
延設部材１２のねじ部材１１に対する位相をずらし、こ
の位相をずらすときに生じる摩擦で端部１１Ｂと円孔２
０のはめあい面及び密接する端面１１Ｃと底面２２同士
を焼付かせることによって、ねじ部材１１の端部１１Ｂ
に延設部材１２が接合される。その後、機械加工によっ
て、延設部材１２に支持部１３、部品取付部１４及びカ
ラー相当部１５が形成される（図１（ｂ）参照）。After shrink fitting, the extension member 12 is twisted to shift the phase of the extension member 12 with respect to the screw member 11, and the end portion 11B and the circular hole 2 are formed by friction generated when the phase is shifted.
The end face 11B of the screw member 11 is formed by baking the bottom face 22 and the end face 11C, which are in contact with each other, and the closely fitting end face 11C.
The extension member 12 is joined to the second member. Thereafter, the support portion 13, the component mounting portion 14, and the collar equivalent portion 15 are formed on the extension member 12 by machining (see FIG. 1B).

【００４６】この第４の実施の形態によれば、ねじ部材
１１は在庫生産された転造ねじ軸又は研削ねじ軸を切断
したものであるから、製作コストを従来のものより廉価
にすることができる。また、ねじ部材１１の端部１１Ｂ
に円孔２０を、円孔２０の底面２２がねじ部材１１の端
面１１Ｃに密接するように焼ばめした後、延設部材１２
にねじりを与えて延設部材１２のねじ部材１１に対する
位相をずらし、この位相をずらすときに生じる摩擦で端
部１１Ｂと円孔２０のはめあい面及び密接するねじ部材
１１の端面１１Ｃと円孔２０の底面２２同士を焼付かせ
るようにしたので、ねじ部材１１と延設部材１２（機械
加工後は、支持部１３、部品取付部１４及びカラー相当
部１５からなる延設部材）の接合をより強固にすること
ができる。このため、図１（ｂ）のねじ軸１０が駆動手
段（図示せず。）によって回転駆動される際、作用する
ねじりモーメント又は反転時の衝撃によって、支持部１
３、部品取付部１４及びカラー相当部１５からなる延設
部材に対するねじ部材１１の位相、すなわち、円孔２０
に対する端部１１Ｂの位相がずれる虞はない。According to the fourth embodiment, since the screw member 11 is formed by cutting a rolled screw shaft or a ground screw shaft which is manufactured in stock, the manufacturing cost can be made lower than the conventional one. it can. Also, the end 11B of the screw member 11
After shrink-fitting the circular hole 20 so that the bottom surface 22 of the circular hole 20 is in close contact with the end surface 11C of the screw member 11,
, The phase of the extending member 12 with respect to the screw member 11 is shifted, and the friction generated when shifting the phase causes the fitting surface between the end portion 11B and the circular hole 20 and the end surface 11C of the screw member 11 to be in close contact with the circular hole 20. The bottom surfaces 22 are made to stick to each other, so that the screw member 11 and the extension member 12 (after machining, the extension member composed of the support portion 13, the component mounting portion 14, and the collar equivalent portion 15) are more firmly joined. Can be For this reason, when the screw shaft 10 of FIG. 1B is rotationally driven by a driving means (not shown), the supporting portion 1 is caused by a torsional moment acting or an impact at the time of reversal.
3. The phase of the screw member 11 with respect to the extended member including the component mounting portion 14 and the collar equivalent portion 15, that is, the circular hole 20
There is no possibility that the phase of the end 11B is shifted with respect to.

【００４７】図７は、本発明の第５の実施の形態を示
す。この第５の実施の形態は、上述の第４の実施の形態
の変形態様である。なお、第４の実施の形態と同一又は
相当部分には同一の符号を付して、その説明は省略す
る。同図（ａ）及び（ｂ）に示すように、延設部材１２
の端面２１に穿設された深さＬ13の円孔２０の内周面に
は、端部１１Ｂのねじ溝１１Ｄと相補う形状の突条２３
が螺刻されている（研削又はラップ仕上げが好まし
い。）。そして、この突条２３のボールピッチ円径Ｙ
は、ねじ溝１１Ｄのボールピッチ円径Ｗに対して Ｙ＝
Ｗ−δ（式中、δは焼ばめしろ）の関係を満足するよう
に形成されている。なお、この第５の実施の形態では、
ねじ溝１１Ｄと突条２３の螺接面がはめあい面となるの
で、ねじ部材１１が転造ねじ軸であっても端部１１Ｂの
外径を再加工する必要はない。また、符号２４は、突条
２３を螺刻するための中ぐり逃げ孔を示す。FIG. 7 shows a fifth embodiment of the present invention. This fifth embodiment is a modification of the above-described fourth embodiment. The same or corresponding parts as in the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIGS.
The inner peripheral surface of the circular hole 20 of the bored depth L 13 in the end face 21 of the complement each shape as the thread groove 11D of the end portion 11B protruding 23
Is threaded (grinding or lapping is preferred). And the ball pitch circle diameter Y of the ridge 23
Is equal to the ball pitch circle diameter W of the thread groove 11D.
It is formed so as to satisfy the relationship of W-δ (where δ is an interference fit). In the fifth embodiment,
Since the screw contact surface between the screw groove 11D and the ridge 23 is a fitting surface, it is not necessary to rework the outer diameter of the end 11B even if the screw member 11 is a rolled screw shaft. Reference numeral 24 denotes a borehole for threading the ridge 23.

【００４８】次に、第４の実施の形態と同様に具体的な
数値を挙げて、この第５の実施の形態における焼ばめ仕
様を説明する。Ｗ＝４．２ｍｍ，Ｙ＝Ｗ−δ＝４．２ｍ
ｍ−δ，Ｖ＝９．５ｍｍとし、ねじ部材１１及び延設部
材１２の材質を調質炭素鋼Ｓ５５Ｃとする。また、炭素
鋼Ｓ５５Ｃの許容せん断応力τmax、縦弾性係数Ｅ及び
線膨張係数αをそれぞれ第４の実施の形態における値と
すれば、前述の式（１），（２）及び（３）から、ｐ≒
７．７×９．８Ｎ／ｍｍ2，δ≒４×１０-3ｍｍ，及び
ｔ≒８３℃ になる。そこで、第４の実施の形態と同様
に、ねじ部材１１と延設部材１２間の温度差ｔを１８０
℃ とする。そして、図７（ｃ）に示すように、突条２
３を端部１１Ｂのねじ溝１１Ｄに手動で螺合させなが
ら、円孔２０の底面２２がねじ部材１１の端面１１Ｃに
密接するように焼ばめする。なお、ねじ部材１１（１条
ねじとする。）の諸元を、第４の実施の形態と同様に、
Ｐ＝Ｓ＝４．０ｍｍ，Ｑ＝３．３ｍｍとし、リード及び
ボール径をそれぞれ１ｍｍ及び０．８ｍｍとする。ま
た、Ｌ13＝７ｍｍとする。Next, the shrink fit specification in the fifth embodiment will be described by giving specific numerical values in the same manner as in the fourth embodiment. W = 4.2 mm, Y = W−δ = 4.2 m
m−δ, V = 9.5 mm, and the materials of the screw member 11 and the extension member 12 are tempered carbon steel S55C. If the allowable shear stress τ max , the longitudinal elastic modulus E, and the linear expansion coefficient α of the carbon steel S55C are the values in the fourth embodiment, respectively, the above equations (1), (2), and (3) , P ≒
7.7 × 9.8 N / mm 2 , δ ≒ 4 × 10 −3 mm, and t ≒ 83 ° C. Therefore, similarly to the fourth embodiment, the temperature difference t between the screw member 11 and the extension member 12 is set to 180.
° C. Then, as shown in FIG.
The screw 3 is manually screwed into the screw groove 11D of the end 11B and shrink-fitted so that the bottom surface 22 of the circular hole 20 is in close contact with the end surface 11C of the screw member 11. Note that the specifications of the screw member 11 (referred to as a single thread) are the same as in the fourth embodiment.
P = S = 4.0 mm, Q = 3.3 mm, and the lead and ball diameters are 1 mm and 0.8 mm, respectively. L 13 = 7 mm.

【００４９】焼ばめ後、螺合する突条２２とねじ溝１１
Ｄをねじ込む方向のねじりを延設部材１２に与えて延設
部材１２のねじ部材１１に対する位相をずらし、この位
相をずらすときに生じる摩擦で突条２２とねじ溝１１Ｄ
の螺接面、及び密接する端面１１Ｃと底面２２同士を焼
付かせることによって、ねじ部材１１の端部１１Ｂに延
設部材１２が接合される。その後、機械加工によって、
延設部材１２に支持部１３、部品取付部１４及びカラー
相当部１５が形成される（図１（ｂ）参照）。After shrink fitting, the projecting ridge 22 and the screw groove 11 to be screwed together
D is screwed in the direction of screwing to the extending member 12 to shift the phase of the extending member 12 with respect to the screw member 11, and the ridge 22 and the screw groove 11 </ b> D are generated by friction generated when the phase is shifted.
The extension member 12 is joined to the end portion 11B of the screw member 11 by baking the screw contact surface and the closely contacting end surface 11C and the bottom surface 22 with each other. Then, by machining
A support portion 13, a component mounting portion 14, and a collar equivalent portion 15 are formed on the extension member 12 (see FIG. 1B).

【００５０】この第５の実施の形態によれば、突条２２
とねじ溝１１Ｄが螺合しているから、第４の実施の形態
より接合が強固になる。また、ねじ部材１１から延設部
材１２（機械加工後は、支持部１３、部品取付部１４及
びカラー相当部１５からなる延設部材）が抜脱する虞は
ない。その他の作用は第４の実施の形態と同様であるの
で、その説明は省略する。According to the fifth embodiment, the ridge 22
And the screw groove 11D are screwed together, so that the bonding is stronger than in the fourth embodiment. Further, there is no possibility that the extension member 12 (the extension member including the support portion 13, the component mounting portion 14, and the collar equivalent portion 15 after the machining) is removed from the screw member 11. Other operations are the same as those of the fourth embodiment, and the description thereof is omitted.

【００５１】なお、上述の実施の形態では、ねじ部材に
延設部材を接合後、機械加工によって、この延設部材に
支持部等を形成したボールねじのねじ軸を例示したが、
ねじ部材に予め支持部等が形成された延設部材を接合す
ることもできる。In the above-described embodiment, the screw shaft of the ball screw in which the support member and the like are formed on the extended member by machining after joining the extended member to the screw member has been described.
An extension member in which a support portion or the like is formed in advance can be joined to the screw member.

【００５２】[0052]

【発明の効果】本発明の請求項１〜５に係るボールねじ
のねじ軸によれば、 （１）ねじ部材は在庫生産された転造ねじ軸又は研削ね
じ軸を切断したものであるから、製作コストを従来のも
のより廉価にすることができる。 （２）焼ばめ後、はめあい面及び密接面同士を焼付かせ
るようにしたので、ねじ部材と延設部材（機械加工後
は、支持部等からなる延設部材）の接合をより強固にす
ることができる。このため、ねじ軸が駆動手段によって
回転駆動される際、作用するねじりモーメント又は反転
時の衝撃によって、支持部等からなる延設部材に対する
ねじ部材の位相がずれる虞はない。また、本発明の請求
項２，３及び５に係るボールねじのねじ軸によれば、突
出軸と円孔（請求項２，３）、または、ねじ溝と円孔
（請求項５）を係合させるようにしたので、ねじ部材か
ら延設部材（機械加工後は、支持部等からなる延設部
材）が抜脱する虞はない。特に、請求項３に係るボール
ねじのねじ軸によれば、ねじ軸に予張力を付与すること
ができる。According to the screw shaft of the ball screw according to the first to fifth aspects of the present invention, (1) Since the screw member is obtained by cutting a rolled screw shaft or a ground screw shaft which is manufactured in stock, The production cost can be made lower than the conventional one. (2) After the shrink fitting, the fitting surface and the close contact surface are made to seize each other, so that the joining between the screw member and the extending member (after machining, the extending member including the support portion and the like) is further strengthened. be able to. For this reason, when the screw shaft is rotationally driven by the driving means, there is no possibility that the phase of the screw member is shifted with respect to the extended member including the support portion due to the torsional moment acting or the impact at the time of reversal. According to the screw shaft of the ball screw according to claims 2, 3 and 5 of the present invention, the projecting shaft and the circular hole (claims 2 and 3) or the screw groove and the circular hole (claim 5) are related. Since it is made to fit, there is no danger that the extended member (extended member composed of a support portion or the like after machining) will come off from the screw member. In particular, according to the screw shaft of the ball screw according to the third aspect, a pretension can be applied to the screw shaft.

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

【図１】 本発明におけるボールねじのねじ軸を示す正
面図であり、同図（ａ）及び（ｂ）は、それぞれ、ねじ
部材の端面に延設部材が接合されたねじ軸、及びねじ部
材の端部に延設部材が接合されたねじ軸の正面図。FIG. 1 is a front view showing a screw shaft of a ball screw according to the present invention. FIGS. 1 (a) and 1 (b) show a screw shaft in which an extended member is joined to an end surface of a screw member, and a screw member, respectively. The front view of the screw shaft with which the extension member was joined to the end part of.

【図２】 本発明の第１の実施の形態を示す要部断面図
であり、同図（ａ），（ｂ）及び（ｃ）は、それぞれ、
ねじ部材の要部、延設部材の要部、及びねじ部材と延設
部材の接合要部の断面図。FIGS. 2A and 2B are cross-sectional views of main parts showing a first embodiment of the present invention, wherein FIGS.
Sectional drawing of the principal part of a screw member, the principal part of an extension member, and the joining principal part of a screw member and an extension member.

【図３】 焼ばめしろ、及び焼ばめしろを得るために必
要な温度差の算出式の説明図。FIG. 3 is an explanatory diagram of a shrink fit and a formula for calculating a temperature difference required to obtain the shrink fit.

【図４】 本発明の第２の実施の形態を示す要部断面図
であり、同図（ａ），（ｂ）及び（ｃ）は、それぞれ、
ねじ部材の要部、延設部材の要部、及びねじ部材と延設
部材の接合要部の断面図。FIG. 4 is a sectional view of a main part showing a second embodiment of the present invention, wherein FIGS. 4 (a), 4 (b) and 4 (c) are respectively
Sectional drawing of the principal part of a screw member, the principal part of an extension member, and the joining principal part of a screw member and an extension member.

【図５】 本発明の第３の実施の形態を示す要部断面図
であり、同図（ａ），（ｂ）及び（ｃ）は、それぞれ、
ねじ部材の要部、延設部材の要部、及びねじ部材と延設
部材の接合要部の断面図。FIG. 5 is a sectional view of a main part showing a third embodiment of the present invention, and FIGS. 5 (a), 5 (b) and 5 (c) are respectively
Sectional drawing of the principal part of a screw member, the principal part of an extension member, and the joining principal part of a screw member and an extension member.

【図６】 本発明の第４の実施の形態を示す要部断面図
であり、同図（ａ），（ｂ）及び（ｃ）は、それぞれ、
ねじ部材の要部、延設部材の要部、及びねじ部材と延設
部材の接合要部の断面図。FIG. 6 is a sectional view of a main part showing a fourth embodiment of the present invention, wherein FIGS. 6 (a), 6 (b) and 6 (c) are respectively
Sectional drawing of the principal part of a screw member, the principal part of an extension member, and the joining principal part of a screw member and an extension member.

【図７】 本発明の第５の実施の形態を示す要部断面図
であり、同図（ａ）及び（ｂ）は、それぞれ、延設部材
の要部、及びねじ部材と延設部材の接合要部の拡大断面
図。FIGS. 7A and 7B are cross-sectional views of a main part showing a fifth embodiment of the present invention. FIGS. 7A and 7B are main parts of an extension member, and a screw member and an extension member, respectively. FIG. 4 is an enlarged cross-sectional view of a main part of the joint.

【符号の説明】[Explanation of symbols]

１，１０ ねじ軸 ２，１１ ねじ部材 ２Ａ，１１Ａ ねじ部材の外周面 ３，７，１２ 延設部材 １１Ｂ ねじ部材の端部 １１Ｃ，１７ ねじ部材の端面 １１Ｄ ねじ溝 １６ 突出軸 １６Ａ 突出軸の小径部 １６Ｂ 突出軸の大径部 １６Ｃ 突出軸の大径部 １６Ｄ 突出軸の小径の三角雄ねじ部 １１Ｃ，１７ ねじ部材の端面 １８，２０ 円孔 １８Ａ 円孔の小径部 １８Ｂ 円孔の大径部 １８Ｃ 円孔の大径部 １８Ｄ 円孔の小径の三角雌ねじ部 １９ 延設部材の端面 ２２ 円孔の底面 1,10 Screw shaft 2,11 Screw member 2A, 11A Outer peripheral surface of screw member 3,7,12 Extension member 11B End of screw member 11C, 17 End surface of screw member 11D Screw groove 16 Projection shaft 16A Small diameter of projection shaft Part 16B Large diameter part of protruding shaft 16C Large diameter part of protruding shaft 16D Triangular male screw part of small diameter of protruding shaft 11C, 17 End face of screw member 18, 20 Circular hole 18A Small diameter part of circular hole 18B Large diameter part of circular hole 18C Large diameter part of circular hole 18D Triangular female screw part of small diameter of circular hole 19 End face of extension member 22 Bottom of circular hole

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 予め外周面にねじ溝が全長に亘って形成
されたねじ部材と、該ねじ部材の少なくとも一方の端面
に接合された延設部材とからなるボールねじのねじ軸で
あって、 前記ねじ部材と前記延設部材は同一の材質からなり、該
延設部材が接合される前に、前記ねじ部材の外周面が高
周波焼入れ又は浸炭焼入れによって表面硬化されるとと
もに仕上げ加工されており、 前記ねじ部材の端面に突設された前記ねじ溝の谷径より
小径の突出軸に、前記延設部材の端面に穿設された円孔
を、前記延設部材の端面が前記ねじ部材の端面に密接す
るように焼ばめした後、前記延設部材にねじりを与えて
該延設部材の前記ねじ部材に対する位相をずらし、該位
相をずらすときに生じる摩擦で前記突出軸と前記円孔の
はめあい面及び前記ねじ部材と前記延設部材の密接する
端面同士を焼付かせることによって前記ねじ部材の端面
に前記延設部材が接合されていることを特徴とする、 ボールねじのねじ軸。1. A screw shaft of a ball screw, comprising: a screw member in which a screw groove is formed in advance on the outer peripheral surface over the entire length; and an extended member joined to at least one end surface of the screw member. The screw member and the extension member are made of the same material, and before the extension member is joined, the outer peripheral surface of the screw member is surface-hardened by induction hardening or carburizing and finishing is performed, A circular hole formed in the end surface of the extending member is formed on a projecting shaft having a diameter smaller than the root diameter of the screw groove protruding from the end surface of the screw member, and the end surface of the extending member is formed on the end surface of the screw member. After being shrink-fitted so as to be in close contact with each other, the extension member is twisted to shift the phase of the extension member with respect to the screw member, and the friction generated when shifting the phase causes the protrusion shaft and the circular hole to slide. The fitting surface and the screw member and the Wherein the extending member to the end face of the screw member by causing adhere baked end faces closely the portion member is bonded, the screw shaft of the ball screw. 【請求項２】 前記突出軸と前記円孔は、それぞれ、前
記ねじ部材及び前記延設部材の各端面側から互いに対応
する小径部と大径部とからなる段付き形状である、請求
項１のボールねじのねじ軸。2. The protruding shaft and the circular hole have a stepped shape including a small-diameter portion and a large-diameter portion corresponding to each other from the end surfaces of the screw member and the extension member, respectively. Ball screw screw shaft. 【請求項３】 前記突出軸と前記円孔は、それぞれ、前
記ねじ部材及び前記延設部材の各端面側から互いに対応
する大径部と小径の三角ねじ部とからなる段付き形状で
ある、請求項１のボールねじのねじ軸。3. The projecting shaft and the circular hole have a stepped shape including a large-diameter portion and a small-diameter triangular screw portion respectively corresponding to each end face side of the screw member and the extension member. A screw shaft of the ball screw according to claim 1. 【請求項４】 予め外周面にねじ溝が全長に亘って形成
されたねじ部材と、該ねじ部材の少なくとも一方の端部
に接合された延設部材とからなるボールねじのねじ軸で
あって、 前記ねじ部材と前記延設部材は同一の材質からなり、該
延設部材が接合される前に、前記ねじ部材の外周面が高
周波焼入れ又は浸炭焼入れによって表面硬化されるとと
もに仕上げ加工されており、 前記ねじ部材の端部に、前記延設部材の端面に穿設され
た円孔を、該円孔の底面が前記ねじ部材の端面に密接す
るように焼ばめした後、前記延設部材にねじりを与えて
該延設部材の前記ねじ部材に対する位相をずらし、該位
相をずらすときに生じる摩擦で前記ねじ部材の端部と前
記円孔のはめあい面及び密接する前記ねじ部材の端面と
前記円孔の底面同士を焼付かせることによって前記ねじ
部材の端部に前記延設部材が接合されていることを特徴
とする、 ボールねじのねじ軸。4. A screw shaft of a ball screw comprising: a screw member in which a screw groove is formed in the outer peripheral surface over the entire length in advance; and an extended member joined to at least one end of the screw member. The screw member and the extension member are made of the same material, and before the extension member is joined, the outer peripheral surface of the screw member is surface hardened by induction hardening or carburizing quenching and finished. After shrink-fitting a circular hole formed in the end surface of the extending member at the end of the screw member so that the bottom surface of the circular hole is in close contact with the end surface of the screw member, The phase of the extending member is shifted with respect to the screw member by giving a torsion to the end portion of the screw member and the fitting surface of the circular hole and the end surface of the screw member that are in close contact with each other by friction generated when the phase is shifted. Burn the bottoms of the holes Wherein the extending member to the end portion of the screw member are joined by the screw shaft of the ball screw. 【請求項５】 前記円孔に設けた前記ねじ溝と相補う形
状の突条が前記ねじ溝に螺合されている、請求項４のボ
ールねじのねじ軸。5. The screw shaft of a ball screw according to claim 4, wherein a ridge having a shape complementary to said screw groove provided in said circular hole is screwed into said screw groove.
JP2001021001A 2001-01-30 2001-01-30 Ball screw screw shaft Expired - Lifetime JP4549549B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001021001A JP4549549B2 (en) 2001-01-30 2001-01-30 Ball screw screw shaft

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007010117A (en) * 2005-07-04 2007-01-18 Kss Kk Shaft member and electric linear actuator using thereof
JP2007211940A (en) * 2006-02-13 2007-08-23 Sus Corp Linear motion device
JP2015037377A (en) * 2013-08-16 2015-02-23 台達電子工業股▲ふん▼有限公司 Electrically-driven linear actuator and electric motor therefor
JP2015150627A (en) * 2014-02-12 2015-08-24 株式会社ジェイテクト Shrink fitting method and shrink fitting device

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0893928A (en) * 1994-09-27 1996-04-12 Yamatake Honeywell Co Ltd Valve device and method for manufacture thereof
JPH08285030A (en) * 1995-04-10 1996-11-01 Thk Kk Ball screw and manufacture thereof
JPH1182829A (en) * 1997-09-16 1999-03-26 Nippon Steel Corp Friction welding tube fitting
JP2000287831A (en) * 1999-04-08 2000-10-17 Fuji Hensokuki Co Ltd Connection structure of open/close drive transmission of sheet
JP2000291769A (en) * 1999-04-07 2000-10-20 Ntn Corp Ball screw
JP2000343246A (en) * 1999-06-03 2000-12-12 Mitsubishi Motors Corp Structure of friction welding part for axial member and friction welding method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0893928A (en) * 1994-09-27 1996-04-12 Yamatake Honeywell Co Ltd Valve device and method for manufacture thereof
JPH08285030A (en) * 1995-04-10 1996-11-01 Thk Kk Ball screw and manufacture thereof
JPH1182829A (en) * 1997-09-16 1999-03-26 Nippon Steel Corp Friction welding tube fitting
JP2000291769A (en) * 1999-04-07 2000-10-20 Ntn Corp Ball screw
JP2000287831A (en) * 1999-04-08 2000-10-17 Fuji Hensokuki Co Ltd Connection structure of open/close drive transmission of sheet
JP2000343246A (en) * 1999-06-03 2000-12-12 Mitsubishi Motors Corp Structure of friction welding part for axial member and friction welding method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007010117A (en) * 2005-07-04 2007-01-18 Kss Kk Shaft member and electric linear actuator using thereof
JP2007211940A (en) * 2006-02-13 2007-08-23 Sus Corp Linear motion device
JP2015037377A (en) * 2013-08-16 2015-02-23 台達電子工業股▲ふん▼有限公司 Electrically-driven linear actuator and electric motor therefor
JP2015150627A (en) * 2014-02-12 2015-08-24 株式会社ジェイテクト Shrink fitting method and shrink fitting device

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