JP2014167333A

JP2014167333A - Locking screw

Info

Publication number: JP2014167333A
Application number: JP2013039585A
Authority: JP
Inventors: Yasunobu Kakuma; 康宣角間
Original assignee: Nitto Seiko Co Ltd
Current assignee: Nitto Seiko Co Ltd
Priority date: 2013-02-28
Filing date: 2013-02-28
Publication date: 2014-09-11
Anticipated expiration: 2033-02-28
Also published as: JP6592227B2

Abstract

PROBLEM TO BE SOLVED: To provide a locking screw of high locking effect when a member to be fastened is fastened to a mating member formed with a female screw.SOLUTION: A locking screw 1 of this invention is made such that a following flank 6 of a screw thread 4 is formed as a plurality of steps. With this configuration, since all the apex angles 6a, 6b, 6s, 6d at each of the steps formed at the following flank 6 are engaged with female threads 11 at the time of fastening operation, it is possible to attain a high locking effect. In addition, the apex angles 6a, 6b, 6s, 6d at each of the steps in the following flank 6 of the screw thread 4 are set on imaginary flanks placed at symmetrical position to a leading flank 5. With this configuration, since these apex angles 6a, 6b, 6s, 6d are most deeply engaged with the female thread 11 when fastened under such a range as one in which they are not contacted with the female thread 11, they may be easily engaged and a high locking effect can be attained.

Description

本発明は、めねじが成形された相手部材に被締結部材を締結するに際して使用されるゆるみ止め効果の高いゆるみ止めねじに関するものである。 The present invention relates to a locking screw having a high locking effect used when a fastened member is fastened to a mating member on which a female screw is formed.

従来、振動等の発生によりゆるみの発生し易い個所に配置された相手部材に被締結部材を締結するに際しては、ゆるみ止めねじが使用されている。ゆるみ止めねじが小ねじである場合、そのゆるみ止め効果、すなわち締結力はねじ山フランクの摩擦から得られることが知られており、ねじ山フランクの摩擦増の工夫が種々行われている。中でも、ねじ山フランクに突起を設けることによってねじ山フランクの摩擦増を図ったゆるみ止めねじはゆるみ止め効果の高いことから、各方面で使用されている。このゆるみ止めねじの一例として、特許文献１に記載のゆるみ止めねじがある。このゆるみ止めねじは、ねじ山フランクのうち、追い側フランクが複合角を成しており、締め付け時には追い側フランクの先端角部がめねじに食い込むことにより、ゆるみ止め効果を発揮するものである。 2. Description of the Related Art Conventionally, when a member to be fastened is fastened to a mating member arranged at a place where loosening is likely to occur due to vibration or the like, a locking screw is used. When the locking screw is a small screw, it is known that the locking effect, that is, the fastening force, is obtained from the friction of the thread flank, and various attempts have been made to increase the friction of the thread flank. Among them, the locking screws that increase the friction of the thread flank by providing protrusions on the thread flank are used in various directions because they have a high locking effect. As an example of the locking screw, there is a locking screw described in Patent Document 1. This loosening set screw has a compound flank among the thread flank and forms a compound angle. When tightening, the tip corner of the follower flank bites into the female screw, thereby exhibiting a loosening prevention effect.

特開２００６−５７８０１号公報JP 2006-57801 A

上記ゆるみ止めねじの場合、締め付け時にめねじに対して食い込むのは、追い側フランクの先端角部だけであるため、十分なゆるみ止め効果が得られないという問題が生じている。 In the case of the above-described locking screw, only the tip corner portion of the follower flank bites into the female screw when tightening, so that there is a problem that a sufficient locking effect cannot be obtained.

本発明の目的は、上記問題を除去することであり、ゆるみ止め効果の高いゆるみ止めねじを提供することである。 An object of the present invention is to eliminate the above-mentioned problem and to provide a locking screw having a high locking effect.

本発明は、上記目的を達成するために、ねじ山の追い側フランクが複数段形状に形成されていることを特徴とする。この構成によれば、締め付け時には締結力（軸力）の作用により、めねじと追い側フランクが接近し、追い側フランクに形成された各段部の頂角が全てめねじに食い込むため、高いゆるみ止め効果が得られる。 In order to achieve the above object, the present invention is characterized in that the follower flank of the thread is formed in a plurality of steps. According to this configuration, when tightening, due to the action of the fastening force (axial force), the female screw and the follower flank approach each other, and the apex angles of the respective step portions formed on the follower flank all bite into the female screw. A loosening prevention effect is obtained.

また、ねじ山の追い側フランクにおいては各段部の頂角が、ねじ山の中心線を対称軸として進み側フランクと対称な位置にある仮想フランク上に設定されていることが好ましい。この構成によれば、追い側フランクは、ねじ込み時にはめねじに接触せず、締め付け時には最もめねじに接近する位置となる。つまり、追い側フランクの各段部の頂角が、ねじ込み時にはめねじに接触しない範囲で、締結時にはめねじに最も深く食い込むことになるので、ねじ込み易く、かつ高いゆるみ止め効果が得られる。 In the thread flank flank, it is preferable that the apex angle of each step is set on a virtual flank that is symmetrical to the advance flank with the thread center line as the axis of symmetry. According to this configuration, the follower flank does not come into contact with the female screw when screwed, and is positioned closest to the female screw when tightened. In other words, since the apex angle of each step portion of the follower flank does not contact the female screw at the time of screwing, it deeply bites into the female screw at the time of fastening, so that it is easy to screw in and a high locking prevention effect is obtained.

以上説明した本発明によれば、めねじが成形された相手部材に被締結部材を締結するに際して、締結力（軸力）の作用によってねじ山の追い側フランクに形成された各段部の頂角が全てめねじに食い込むことにより、ゆるみ止め効果を増大させたゆるみ止めねじを提供することができる。 According to the present invention described above, when the member to be fastened is fastened to the mating member on which the female screw is formed, the top of each step portion formed on the follower flank of the screw thread by the action of the fastening force (axial force). By having all the corners bite into the female screw, it is possible to provide a locking screw with an increased locking effect.

本発明の実施形態に係るゆるみ止めねじの正面図。The front view of the locking screw which concerns on embodiment of this invention. 本発明の実施形態に係るゆるみ止めねじの要部拡大断面図であり、（ａ）はねじ込み状態、（ｂ）は締め付け状態を示す。It is a principal part expanded sectional view of the locking screw which concerns on embodiment of this invention, (a) is a screwed state and (b) shows a clamping | tightening state.

以下、本発明の実施形態に係るゆるみ止めねじを、図面を参照して説明する。本発明の実施形態に係るゆるみ止めねじ１は、図１に示すように、ドライバビット（図示せず）の回転が伝達される駆動穴２ａを備えたねじ頭部２と、ねじ頭部２の中心から延びるねじ部３とを備えており、めねじ１１が成形された相手部材１０に被締結部材２０を締結する場合に使用する。このようなゆるみ止めねじ１は、一般的に小ねじと称される。 Hereinafter, a locking screw according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a locking screw 1 according to an embodiment of the present invention includes a screw head 2 having a drive hole 2 a to which rotation of a driver bit (not shown) is transmitted, and a screw head 2. And a threaded portion 3 extending from the center, and is used when the fastened member 20 is fastened to the mating member 10 formed with the female screw 11. Such a locking screw 1 is generally called a machine screw.

図２において、前記ねじ部３に形成されたねじ山４は、追い側フランク６の斜面形状を除いて日本工業規格Ｂ０２０５（一般用メートルねじ）に準じた山形を成している。したがって、ねじ山４の角度は６０°、並びにねじ先端側に位置する進み側フランク５及びねじ頭部側に位置する追い側フランク６は、双方共にねじ山の中心線に対して傾斜角３０°に設定されている。また、めねじ１１のねじ山角度も６０°に設定されており、ねじ山の両フランク５，６は対向するめねじ山と平行している。 In FIG. 2, the thread 4 formed on the thread portion 3 has a chevron conforming to Japanese Industrial Standard B0205 (general metric thread) except for the slope shape of the follower flank 6. Accordingly, the angle of the screw thread 4 is 60 °, and both the advance flank 5 located on the screw tip side and the follower flank 6 located on the screw head side are both inclined by 30 ° with respect to the center line of the screw thread. Is set to The thread angle of the female thread 11 is also set to 60 °, and both flanks 5 and 6 of the thread are parallel to the opposing female thread.

前記ねじ山の進み側フランク５は、平坦面に形成されている。一方、追い側フランク６は、ねじ山４の頂部から基部にかけて４段形状に形成されており、各段部に頂角６ａ，６ｂ，６ｃ，６ｄを有している。これら頂角６ａ，６ｂ，６ｃ，６ｄは、ねじ山４の中心線を対称軸として進み側フランク５と対称な位置にある仮想フランク上に設定されている。また、前記追い側フランク６において上下の段部を連ねる側壁は、ねじ山４の中心線に対して僅かに傾斜しており、仮想フランクよりも急傾斜に形成されている。このような段形状は、ねじ山４の追い側フランク６に全周に渡って形成されている。なお、追い側フランク６の段形状は、複数段に形成されていれば３段、５段でもよく、段数に応じた相応のゆるみ止め効果が発揮される。 The thread advance side flank 5 is formed on a flat surface. On the other hand, the follower side flank 6 is formed in a four-step shape from the top of the screw thread 4 to the base, and has apex angles 6a, 6b, 6c, 6d at each step. These apex angles 6 a, 6 b, 6 c, 6 d are set on virtual flank that is symmetrical to the advance side flank 5 with the center line of the thread 4 as the axis of symmetry. Further, the side wall connecting the upper and lower step portions in the follower side flank 6 is slightly inclined with respect to the center line of the screw thread 4 and is formed to be steeper than the virtual flank. Such a step shape is formed over the entire circumference of the follower flank 6 of the screw thread 4. The step shape of the follower flank 6 may be three or five as long as the follower flank 6 is formed in a plurality of steps, and an appropriate loosening prevention effect according to the number of steps is exhibited.

上記ゆるみ止めねじ１を使用して、めねじ１１が成形された相手部材１０に被締結部材２０を締結する場合、ねじ込み時には、進み側フランク５は、推力あるいはゆるみ止めねじ１の自重により、めねじ１１に対して僅かに接触する程度であるため、ねじ込みトルクが大幅に増加することもなければ、切粉が大量発生することもない。一方、追い側フランク６は、めねじ１１に対して一切接触しない。これは、追い側フランク６の各段部の頂角６ａ，６ｂ，６ｃ，６ｄが、前記仮想フランク上に設定されていることによるものである。これにより、ねじ込みトルクが増加することもなければ、切粉が発生することもない。 When the fastening member 20 is fastened to the mating member 10 on which the female screw 11 is formed using the above-described locking screw 1, the leading side flank 5 is screwed by the thrust or the own weight of the locking screw 1 during screwing. Since the screw 11 is slightly in contact with the screw 11, the screwing torque does not increase significantly, and a large amount of chips are not generated. On the other hand, the follower flank 6 does not contact the female screw 11 at all. This is due to the fact that the apex angles 6a, 6b, 6c, 6d of the respective step portions of the follower flank 6 are set on the virtual flank. As a result, the screwing torque does not increase and no chips are generated.

一方、締め付け時には、締結力（軸力）の作用により、追い側フランク６がめねじ１１に対して接近し、各段部の頂角６ａ，６ｂ，６ｃ，６ｄが全てめねじに食い込むので、ゆるみ止め効果を増大させることができる。また、追い側フランク６の段部は、全体がめねじ１１に食い込むものではなく、頂角６ａ，６ｂ，６ｃ，６ｄだけが食い込み、各段部を連ねる側壁とめねじ１１との間には隙間が創出されるように構成されている。この構成により、万一切粉が発生しても、当該隙間に切粉が封じこめられるので、切粉が外部へこぼれ落ちる虞もない。なお、本発明の実施形態は、小ねじに限定されるものではなく、タッピンねじに適用することもできる。 On the other hand, at the time of tightening, due to the action of the fastening force (axial force), the follower side flank 6 approaches the female thread 11, and the apex angles 6a, 6b, 6c, 6d of each step portion bite into the female thread, so that they are loosened. The stopping effect can be increased. Further, the stepped portion of the follower flank 6 does not bite into the female screw 11 as a whole, but only the apex angles 6a, 6b, 6c, and 6d bite, and there is a gap between the side wall connecting the stepped portions and the female screw 11. It is configured to be created. With this configuration, even if powder is generated at all, the chips are sealed in the gap, so there is no possibility that the chips spill outside. In addition, embodiment of this invention is not limited to a machine screw, It can also apply to a tapping screw.

１ゆるみ止めねじ
２ねじ頭部
２ａ駆動穴
３ねじ部
４ねじ山
５進み側フランク
６追い側フランク
６ａ，６ｂ，６ｃ，６ｄ頂角
１０相手部材
１１めねじ
２０被締結部材
DESCRIPTION OF SYMBOLS 1 Loosening set screw 2 Screw head 2a Drive hole 3 Screw part 4 Screw thread 5 Advance side flank 6 Follow side flank 6a, 6b, 6c, 6d Vertical angle 10 Opposing member 11 Female thread 20 Fastened member

Claims

A screw for preventing loosening, wherein a follower flank of a screw thread is formed in a plurality of steps.

The apex angle of each step portion in the follower flank of the screw thread is set on a virtual flank that is symmetric with the lead flank of the screw thread with respect to the thread center line. The locking screw according to claim 1.