JPS61153010A - Bolts and method of reinforcing machining of fatigue strength of said bolts - Google Patents
Bolts and method of reinforcing machining of fatigue strength of said boltsInfo
- Publication number
- JPS61153010A JPS61153010A JP27789684A JP27789684A JPS61153010A JP S61153010 A JPS61153010 A JP S61153010A JP 27789684 A JP27789684 A JP 27789684A JP 27789684 A JP27789684 A JP 27789684A JP S61153010 A JPS61153010 A JP S61153010A
- Authority
- JP
- Japan
- Prior art keywords
- bolt
- neck
- bolts
- rounded part
- head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Forging (AREA)
- Connection Of Plates (AREA)
- Insertion Pins And Rivets (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、例えばボルトにおける頭部と軸部との接合す
る首下丸み部の疲労強度を向上させるボルト類およびそ
の疲労強度強化加工方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to bolts that improve the fatigue strength of the rounded part under the neck where the head and shaft of a bolt join together, and a method of processing the fatigue strength reinforcement. .
ボルトは六角状の頭部と、ねじ部が外周に形成された軸
部とから構成され、このボルトの頭部と軸部とが接合す
る個所に首下丸み部が形成されている。そして、ボルト
に疲労を生じた場合、この頭部と軸部とが接合する首下
丸み部の個所からボルトが破断する。The bolt is composed of a hexagonal head and a shaft portion with a threaded portion formed on the outer periphery, and a rounded portion under the neck is formed at the location where the head and shaft portion of the bolt join. When fatigue occurs in the bolt, the bolt breaks at the rounded portion below the neck where the head and shaft portion are joined.
従来、ボルトの首下丸み部の破開防止のためこの首下丸
み部の疲労強度を向上させるようにしているが、その方
法には、ボルトの首下丸み部にロールを添着させ、ボル
トを回転させて首下丸み部を冷間加工をするフィレット
加工方法、あるいはＯ−ルねじによるねＵ転造のように
一対のロール間にボルトを挟持して圧延する強化加工方
法がある。Conventionally, the fatigue strength of the rounded part under the neck of the bolt has been improved in order to prevent it from breaking, but this method involves attaching a roll to the rounded part under the neck of the bolt, There is a fillet processing method in which the rounded part under the neck is cold-worked by rotating the bolt, and a strengthening processing method in which the bolt is held between a pair of rolls and rolled, such as U-roll rolling using an O-hole screw.
（発明が解決しようとする問題点）
上記従来の加工方法では、ボルトもしくはロールを回転
させて加工するため、１個のボルトの加■に費やす時間
は数秒から数十秒を要し、そのため、ボルト類の大量生
産されるものに利用するには生産加工性が悪く、しかも
、この加工方法により形成されたボルトの首下丸み部の
疲労強度はあまり向上されなかった。(Problems to be Solved by the Invention) In the conventional processing method described above, since the bolt or roll is rotated for processing, it takes several seconds to several tens of seconds to apply one bolt. The production processability is poor for use in mass-produced bolts, and furthermore, the fatigue strength of the rounded part under the neck of bolts formed by this processing method was not significantly improved.
本発明は上述のような点に鑑みなされたもので、その第
１の目的は首下丸み部の疲労強度を向上させたボルト類
を提供するものである。The present invention was made in view of the above-mentioned points, and its first purpose is to provide bolts with improved fatigue strength at the rounded portion below the neck.
第２の目的は、そのボルト類の首下丸み部の強化加工を
容易に短時間で行なえ、大量生産にも対応することが可
能なボルト類の疲労強度強化加工方法を提供するもので
ある。The second object is to provide a method for strengthening the fatigue strength of bolts, which can easily strengthen the rounded part under the neck of the bolts in a short time, and which can be applied to mass production.
本発明は、頭部２と軸部３とが接合する首下丸み部４の
曲面径寸法を小さくするかまたは首下丸み部４を頭部２
に喰い込ませて残留圧縮応力を与えたボルト類である。The present invention reduces the curved surface diameter of the under-neck rounded portion 4 where the head 2 and the shaft portion 3 join, or the under-neck rounded portion 4 is
These are bolts that have been bitten into them to give them residual compressive stress.
また、本発明は、型体１１に開口形成された挿通孔１２
にボルト１の軸部３を挿入し、この型体１１に挿入され
たボルト１の頭部２を型体１１に対して押圧してボルト
１の頭部２と軸部３とが接合する首下丸み部４を挿通孔
１２の上端開口縁部の首下丸み形成部１３に押圧し、ボ
ルト１の首下丸み部４の曲面径寸法を小さくするかまた
は首下丸み部４をボルト１の頭部２の下面に喰い込ませ
、ボルト１の首下丸み部４に残留圧縮応力を与えるボル
ト類の疲労強度強化加工方法である。Further, the present invention provides an insertion hole 12 formed in the mold body 11.
The shaft portion 3 of the bolt 1 is inserted into the mold body 11, and the head 2 of the bolt 1 inserted into the mold body 11 is pressed against the mold body 11 to form a neck where the head portion 2 of the bolt 1 and the shaft portion 3 are joined. The lower rounded part 4 is pressed against the lower neck rounded part 13 at the upper opening edge of the insertion hole 12, and the curved surface diameter of the lower neck rounded part 4 of the bolt 1 is reduced, or the lower neck rounded part 4 is pressed against the lower neck rounded part 4 of the bolt 1. This is a processing method for strengthening the fatigue strength of bolts by biting into the lower surface of the head 2 and applying residual compressive stress to the rounded part 4 under the neck of the bolt 1.
本発明は、型体の首下丸み形成部に対してボルト類の首
下丸み部を押圧して、ボルト類の首下丸み部の曲面径寸
法を小さくするかまたは首下丸み部をボルト類の下面に
喰い込ませ、ボルト類の首下丸み部に残留圧縮応力を与
えて、ボルト類の疲労強度強化加工するものである。The present invention presses the under-neck rounded portion of the bolt against the under-neck rounded portion of the mold body to reduce the curved surface diameter of the under-neck rounded portion of the bolt, or This is a process that strengthens the fatigue strength of bolts by biting into the lower surface of the bolt and applying residual compressive stress to the rounded part under the neck of the bolt.
次に本発明の一実施例を図面を参照して説明する。 Next, one embodiment of the present invention will be described with reference to the drawings.
第１図において、１はボルトで、このボルト１は圧造に
より形成され、六角状の頭部２と、ねじ転造が施されて
外周部にねじが形成される軸部３と、頭部２と軸部３と
が接合され軸部３から曲面をもって頭部２の下面に接合
する首下丸み部４とから構成されている。In FIG. 1, 1 is a bolt, and this bolt 1 is formed by heading, and has a hexagonal head 2, a shaft portion 3 that is thread-rolled and has a thread formed on its outer periphery, and a head 2. and a shaft portion 3, and a lower neck rounded portion 4 that is joined to the lower surface of the head 2 with a curved surface from the shaft portion 3.
また、１１は疲労強度強化加工用の型体で、この望体１
１には上下面に開口するとともに上記ボルト１の軸部３
を嵌入しえるほぼ同一径に開口された挿通孔１２が形成
され、この挿通孔１２の上端開口縁部に上記ボルト１の
首下丸み部４の曲面の径寸法より小さい曲面形状に形成
、あるいは同一曲面形状に形成された首下丸み形成部１
３が形成されている。この型体１１の上方には挿通孔１
２に臨んで上下方に進退駆動されるバンチ１５が設けら
れており、型体１１の挿通孔１２に軸部３が挿入された
ボルト１の頭部２をこのバンチ１５が上方から型体１１
の上面に対して押圧する。また、型体１１の挿通孔１２
の下部から押出しビン１６が上下動自在に挿入されてお
り、型体１１の挿通孔１２に挿入されたボルト１の軸部
３の下端に圧接してボルト１を挿通孔１２から押出すよ
うになっている。そして、この押出しビン１６の動作は
、上記バンチ１５がボルト１の頭部２の押圧を終えて上
方に後退すると同時に上方に進出し、この押出しビン１
６によりボルト１を押出した後には、直ちに下方に後退
するようになっている。In addition, 11 is a mold for fatigue strength strengthening processing, and this desired body 1
1 has an opening on the upper and lower surfaces and a shaft portion 3 of the bolt 1.
An insertion hole 12 having approximately the same diameter is formed into which the insertion hole 12 can be inserted, and a curved surface shape smaller than the diameter of the curved surface of the lower neck rounded portion 4 of the bolt 1 is formed at the upper opening edge of the insertion hole 12, or Lower neck roundness forming part 1 formed in the same curved shape
3 is formed. An insertion hole 1 is provided above this mold body 11.
A bunch 15 is provided which faces the mold body 11 and is driven forward and backward in the vertical direction.
Press against the top surface. In addition, the insertion hole 12 of the mold body 11
A push-out pin 16 is inserted from the bottom of the mold body 11 so as to be able to move vertically, and presses against the lower end of the shaft portion 3 of the bolt 1 inserted into the insertion hole 12 of the mold body 11 to push the bolt 1 out of the insertion hole 12. It has become. The operation of the push-out bottle 16 is such that the bunch 15 finishes pressing the head 2 of the bolt 1 and retreats upward, and at the same time advances upward.
After the bolt 1 is pushed out by 6, it immediately retreats downward.
なお、ボルト１の型体１１への供給機構は省略するが、
上記バンチ１５および押出しビン１６の動作に連動させ
るようにすればよい。Note that the mechanism for supplying the bolt 1 to the mold body 11 is omitted;
What is necessary is just to make it interlock with the operation|movement of the said bunch 15 and extrusion bin 16.
そうして、ボルト１の疲労強度強化加工を行なうには、
ボルト供給機構により型体１１の挿通孔１２にボルト１
の軸部３を挿入配置する。Then, in order to strengthen the fatigue strength of bolt 1,
The bolt 1 is inserted into the insertion hole 12 of the mold body 11 by the bolt supply mechanism.
The shaft portion 3 is inserted and arranged.
次に、バンチ１５を下方に前進させて、挿入されたボル
ト１の頭部２を型体１１の上面に対して押圧する。この
バンチ１５による押圧によりボルト１の首下丸み部４に
は、型体１１の首下丸み形成部１３との圧着によりボル
ト１の首下丸み部４の曲面径寸法が僅かに小さくなって
圧縮応力が与えられるか、もしくは、型体１１の首下丸
み形成部１３がボルト１の頭部２の下面に喰い込んで首
下丸み部４に圧縮応力が与えられる。Next, the bunch 15 is advanced downward to press the head 2 of the inserted bolt 1 against the upper surface of the mold body 11. Due to the pressure by the bunch 15, the curved surface diameter of the under-neck rounded portion 4 of the bolt 1 is slightly reduced due to the compression with the under-neck rounded portion 13 of the mold body 11, and the bolt 1 is compressed. A stress is applied, or the under-neck rounded portion 13 of the mold body 11 bites into the lower surface of the head 2 of the bolt 1, and compressive stress is applied to the under-neck rounded portion 4.
次に、バンチ１５を上方に後退させるとともに、押出し
ビン１６を上方に進出させ、ボルト１を型体１１の挿通
孔１２から押出す。このボルト１の押出しの終了ととも
に押出しピン１６は下方に後退する。Next, the bunch 15 is retreated upward, and the pusher pin 16 is advanced upward to push the bolt 1 out of the insertion hole 12 of the mold body 11. At the end of this extrusion of the bolt 1, the extrusion pin 16 retreats downward.
そして、このようにして加工されたボルト１は、その首
下丸み部４に残留圧縮応力が与えられているため疲労強
度が高いものである。The bolt 1 processed in this manner has high fatigue strength because residual compressive stress is applied to the rounded portion 4 under the neck.
なお、この加工方法により、ボルト１は１分間に約６０
〜２００個あるいはそれ以上の個数のボルト１の量産加
工が可能であり、また、この加工における設備は、量産
用としてはりヘッダーを用いるが、型体１１を用意すれ
ばプレス機またはバイスでらよい。In addition, with this processing method, the bolt 1 is heated approximately 60 times per minute.
It is possible to mass-produce up to 200 or more bolts 1, and the equipment used for this processing is a beam header for mass production, but if the mold body 11 is prepared, a press machine or a vise can be used. .
次に、この疲労強度強化加工したボルト１と未加工ボル
トとの比較を以下に示す。Next, a comparison between this bolt 1 subjected to fatigue strength strengthening processing and an unprocessed bolt will be shown below.
首下丸み部４の硬さ分布図を第２図に示しく図中実線は
強化加工品、点線は未加工品）、強化加工を施したボル
ト１の首下丸み部４は、その表面より０．２〜０．３ｍ
＋までの所までは未加工ボルトより２０〜３５ （ＨＶ
２００）上昇し、それより深い所でも１５ （ＨＶ２０
０）程度上昇する。The hardness distribution map of the rounded part 4 under the neck is shown in Fig. 2 (in the figure, the solid line indicates the reinforced product, and the dotted line indicates the unprocessed product). 0.2~0.3m
20 to 35 from the unprocessed bolt up to + (HV
200) rises, and even deeper than that 15 (HV20
0) increase.
また、疲労試験（試験条件は、平均応力＝８１Ｋｇｆ／
ｍｌ ）の結果を第３図の疲れ強さを表わすＳ−Ｎ曲線
図に示しく図中実線は強化加工品、点線は未加工品）、
強化加工を施したボルト１は未加工ボルトよりも疲れ強
さが約２０％上昇した。In addition, fatigue test (test conditions were average stress = 81Kgf/
ml) are shown in the S-N curve diagram representing fatigue strength in Figure 3. In the figure, the solid line is for the strengthened product, and the dotted line is for the unprocessed product).
Bolt 1, which was subjected to reinforcement processing, had approximately 20% higher fatigue strength than the unprocessed bolt.
本発明によれば、ボルト類の首下丸み部に残留圧縮応力
を与えたので、ボルト類の疲労強度を向上することがで
き、また、型体に開口形成された挿通孔にボルト類の軸
部を挿入し、この型体に挿入されたボルト類の頭部を型
体に対して押圧してボルト類の頭部と軸部とが接合する
首下丸み部を挿通孔の上端開口縁部の首下丸み形成部に
押圧し、ボルト類の首下丸み部の曲面径寸法を小さくす
るか、または首下丸み部をボルト類の頭部の下面に喰い
込ませ、ボルト類の首下丸み部に残留圧縮応力を与える
加工方法により、ボルト類を型体に対して押圧するだけ
で容易にかつ短時間でボルト類の首下丸み部の疲労強度
強化加工を施すことができ、生産性が良くボルト類の大
量生産するものの量産加工に対応することができるもの
である。According to the present invention, residual compressive stress is applied to the rounded part under the neck of the bolt, so that the fatigue strength of the bolt can be improved. The head of the bolt inserted into this mold body is pressed against the mold body, and the rounded part under the neck where the head and shaft of the bolt join is connected to the upper opening edge of the insertion hole. Reduce the diameter of the curved surface of the rounded part of the bolt's neck by pressing against the rounded part of the bolt's neck, or press the rounded part of the bolt's neck into the lower surface of the bolt's head to reduce the rounded part of the bolt's neck. By using a processing method that applies residual compressive stress to the bolt, it is possible to easily and quickly strengthen the fatigue strength of the rounded part under the neck of the bolt by simply pressing the bolt against the mold, increasing productivity. It can be used for mass production of bolts and other items that are often mass produced.
第１図は本発明のボルト類およびその疲労強度強化加工
方法の一実施例を示す正面図、第２図は首下丸み部の硬
さ分布図、第３図はＳ−Ｎ曲線図である。
１・・ボルト、２・・頭部、３・・軸部、４・・首下丸
み部、１１・・型体、１２・・挿通孔、１３・・首下丸
み形成部。Fig. 1 is a front view showing an embodiment of the bolts and the fatigue strength strengthening processing method of the present invention, Fig. 2 is a hardness distribution diagram of the rounded part under the neck, and Fig. 3 is an S-N curve diagram. . 1...Bolt, 2...Head, 3...Shaft, 4...Neck rounded part, 11...Mold body, 12...Insertion hole, 13...Neck rounded part.
Claims (2)
み部の曲面径寸法を小さくするかまたは首下丸み部を頭
部に喰い込ませて残留圧縮応力を与えたことを特徴とす
るボルト類。(1) Applying residual compressive stress to the rounded part under the neck where the head and shaft join by reducing the diameter of the curved surface of the rounded part under the neck or by digging the rounded part under the neck into the head. Bolts featuring
挿入し、この型体に挿入されたボルト類の頭部を型体に
対して押圧してボルト類の頭部と軸部とが接合する首下
丸み部を挿通孔の上端開口縁部の首下丸み形成部に押圧
し、ボルト類の首下丸み部の曲面径寸法を小さくするか
または首下丸み部をボルト類の頭部の下面に喰い込ませ
、ボルト類の首下丸み部に残留圧縮応力を与えることを
特徴とする疲労強度強化加工方法。(2) Insert the shaft of the bolt into the insertion hole formed in the mold, press the head of the bolt inserted into the mold against the mold, and press the head of the bolt and shaft. Press the rounded part under the neck where it joins with the rounded part at the upper end of the insertion hole to reduce the diameter of the curved surface of the rounded part under the neck of the bolt, or A fatigue strength strengthening processing method characterized by applying residual compressive stress to the rounded part under the neck of bolts by biting into the lower surface of the head of the bolt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27789684A JPS61153010A (en) | 1984-12-25 | 1984-12-25 | Bolts and method of reinforcing machining of fatigue strength of said bolts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27789684A JPS61153010A (en) | 1984-12-25 | 1984-12-25 | Bolts and method of reinforcing machining of fatigue strength of said bolts |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61153010A true JPS61153010A (en) | 1986-07-11 |
| JPH0261643B2 JPH0261643B2 (en) | 1990-12-20 |
Family
ID=17589794
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27789684A Granted JPS61153010A (en) | 1984-12-25 | 1984-12-25 | Bolts and method of reinforcing machining of fatigue strength of said bolts |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61153010A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6342396A (en) * | 1986-08-04 | 1988-02-23 | ユナイテッド・テクノロジ−ズ・コ−ポレイション | Composite material article enhanced in fatigue strength |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS551139A (en) * | 1978-06-20 | 1980-01-07 | Nippon Telegr & Teleph Corp <Ntt> | Current supply type semiconductor light-emitting device |
-
1984
- 1984-12-25 JP JP27789684A patent/JPS61153010A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS551139A (en) * | 1978-06-20 | 1980-01-07 | Nippon Telegr & Teleph Corp <Ntt> | Current supply type semiconductor light-emitting device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6342396A (en) * | 1986-08-04 | 1988-02-23 | ユナイテッド・テクノロジ−ズ・コ−ポレイション | Composite material article enhanced in fatigue strength |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0261643B2 (en) | 1990-12-20 |
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