JP3164885U

JP3164885U - Locking nut

Info

Publication number: JP3164885U
Application number: JP2010006967U
Authority: JP
Inventors: 芳昭奥野
Original assignee: 大阪フォーミング株式会社
Priority date: 2010-09-30
Filing date: 2010-09-30
Publication date: 2010-12-24
Anticipated expiration: 2020-09-30

Abstract

【課題】緩み止め用リング状弾性板のばね作用による応力と反力でボルトのねじ山を強圧することによりボルトの緩みを確実強固に防止する緩み止めナットを提供する。【解決手段】ナット本体１の上端面にカシメ固定されるリング状弾性板２の内周面に、半径方向内方に突出しかつその突出端がねじ孔の内径とほぼ同径の円弧状に形成された３個の第１〜第３凸状係合片２１〜２３と内面がねじ孔の谷径よりも大径の円弧状に形成された３個の第１〜第３凹状切欠部とを交互に形成する。第１凸状係合片２１はリング状弾性板２と面一状に設けると共に、第２凸状係合片２２は第１凸状係合片２１に対しボルトのねじのリード角に合わせて軸向外方に膨出するように設け、第３凸状係合片２３は第２凸状係合片２２に対しねじのリード角に合わせてさらに軸方向外方に膨出するように設ける。【選択図】図１The present invention provides a locking nut that securely prevents the bolt from loosening by strongly pressing the thread of the bolt with the stress and reaction force of the spring action of the ring-shaped elastic plate for locking. A ring-shaped elastic plate 2 that is caulked and fixed to the upper end surface of a nut body 1 projects radially inward and has a projecting end formed in an arc shape having the same diameter as the inner diameter of a screw hole. The three first to third convex engagement pieces 21 to 23 and the three first to third concave cutouts whose inner surfaces are formed in an arc shape whose diameter is larger than the valley diameter of the screw hole. Alternately formed. The first convex engagement piece 21 is provided flush with the ring-shaped elastic plate 2, and the second convex engagement piece 22 is aligned with the lead angle of the bolt screw with respect to the first convex engagement piece 21. The third convex engagement piece 23 is provided so as to bulge outward in the axial direction in accordance with the lead angle of the screw with respect to the second convex engagement piece 22. . [Selection] Figure 1

Description

本考案は、緩み止めナットに関するものである。 The present invention relates to a locking nut.

従来、緩み止めナットとしては、たとえば中心部に軸方向に貫通するねじ孔が形成されたナット本体の上端面に環状カシメ部が設けられ、そのカシメ部の内部にねじ孔と同心で水平に扁平板状の弾性ワッシャーがカシメ固定される一方、弾性ワッシャーの内周面に、半径方向内方で面一状に突出する複数の凸状係合片と切欠凹部とが等間隔で交互に形成されると共に、各凸状係合片の内周面がねじ孔の内径とほぼ同径の円弧状に形成され、かつ、各凹状切欠部の内周面がねじ孔の谷径よりも大径の円弧状に形成された構成のものが知られている。 Conventionally, as a locking nut, for example, an annular caulking portion is provided at the upper end surface of a nut body in which a screw hole penetrating in the axial direction is formed in the center portion, and the caulking portion is flattened horizontally concentrically with the screw hole. While the flat elastic washer is caulked and fixed, a plurality of convex engaging pieces and notch concaves that protrude in the radial inner direction are alternately formed at equal intervals on the inner peripheral surface of the elastic washer. In addition, the inner peripheral surface of each convex engagement piece is formed in an arc shape having substantially the same diameter as the inner diameter of the screw hole, and the inner peripheral surface of each concave notch is larger in diameter than the valley diameter of the screw hole. The thing of the structure formed in circular arc shape is known.

そして、この緩み止めナットのボルトへの螺入時、上記弾性ワッシャーの凸状係合片をボルトのねじ山の間に入り込ませると共に凸状係合片を変形させながらボルトのねじ山を強圧し、これにより自然回動を防止する摩擦トルクを発生させてナットの緩み止めを図るようにしたものが知られている。 When the locking nut is screwed into the bolt, the convex engagement piece of the elastic washer is inserted between the screw threads of the bolt, and the screw thread of the bolt is strongly pressed while deforming the convex engagement piece. Thus, there has been known one in which a friction torque that prevents natural rotation is generated to prevent the nut from loosening.

ところで、ねじの緩みを防ぐ力を大きくするには、上記弾性ワッシャーの弾性力を大きくすればよく、具体的には、凸状係合片を含む扁平板状の弾性ワッシャーの厚みを大きくすればよい。しかし、単純な一枚の扁平板状となっている弾性ワッシャーの構造によれば、弾性ワッシャーの厚みを大きくしすぎるとボルトのねじ山の間に凸状係合片が入りづらくなるのであり、特に一つ目以降の凸状係合片がボルトのねじ山の間に入りづらくなる問題があった。また、弾性ワッシャーが単純な一枚の扁平板状となっている構成上、螺入が進むにつれて一つ目の凸状係合片が残りの凸状係合片よりも大きく変形することになる。そのため、一つ目の凸状係合片が残りの凸状係合片よりも極端に大きく変形した状態でボルトのねじ山に局部的に強く当接することになり、その結果、局部的に大きな応力がかかってボルトのねじ山を損傷させるといったことがあり、再使用が不能となる問題を有していた。 By the way, in order to increase the force to prevent the screws from loosening, it is sufficient to increase the elastic force of the elastic washer. Specifically, if the thickness of the flat plate-shaped elastic washer including the convex engagement piece is increased. Good. However, according to the structure of the elastic washer having a simple flat plate shape, if the thickness of the elastic washer is too large, the convex engagement piece is difficult to enter between the screw threads of the bolt. In particular, there is a problem that the first and subsequent convex engagement pieces are difficult to enter between the screw threads of the bolts. In addition, since the elastic washer has a simple flat plate shape, the first convex engaging piece is deformed more greatly than the remaining convex engaging pieces as the screwing proceeds. . For this reason, the first convex engaging piece is locally strongly contacted with the thread of the bolt in a state in which the first convex engaging piece is deformed extremely larger than the remaining convex engaging pieces. In some cases, stress is applied and the screw thread of the bolt is damaged, so that it cannot be reused.

そこで、本考案は、凸状係合片の形状を工夫することにより凸状係合片がボルトのねじ山間にスムーズに入り込むことができながら、凸状係合片でねじの緩みを確実に防止でき、その上、ボルトへの傷付きを抑えて再使用が可能な緩み止めナットの提供を課題とする。 Therefore, the present invention devised the shape of the convex engagement piece, so that the convex engagement piece can smoothly enter between the screw threads of the bolt, but the convex engagement piece reliably prevents the screw from loosening. Further, it is an object to provide a locking nut that can be reused while suppressing damage to the bolt.

本願の請求項１記載の考案は、中心部に軸方向に貫通するねじ孔が形成されたナット本体の上端面に環状カシメ部が設けられ、そのカシメ部の内部にねじ孔と同心で水平状に緩み止め用のリング状弾性板がカシメ固定された緩み止めナットにおいて、リング状弾性板の内周面に、半径方向内方に突出しかつその突出端がねじ孔の内径とほぼ同径の円弧状に形成された３個の第１〜第３凸状係合片と、内面がねじ孔の谷径よりも大径の円弧状に形成された３個の第１〜第３凹状切欠部とが交互に形成されている一方、第１〜第３凸状係合片のうち、第１凸状係合片はリング状弾性板と面一状に設けられると共に、第２凸状係合片は第１凸状係合片に対しねじのリード角に合わせて軸方向外方に膨出するように設けられ、第３凸状係合片は第２凸状係合片に対しねじのリード角に合わせてさらに軸方向外方に膨出するように設けられていることを特徴とする。 In the invention according to claim 1 of the present application, an annular caulking portion is provided on the upper end surface of a nut body in which a screw hole penetrating in the axial direction is formed in the center portion, and the caulking portion is concentric with the screw hole and horizontally In a locking nut with a ring-shaped elastic plate for locking it secured to the inner surface of the ring-shaped elastic plate, the inner surface of the ring-shaped elastic plate protrudes inward in the radial direction and the protruding end is a circle having the same diameter as the inner diameter of the screw hole. Three first to third convex engagement pieces formed in an arc shape, and three first to third concave cutout portions formed in an arc shape whose inner surface is larger in diameter than the valley diameter of the screw hole, Are formed alternately. Among the first to third convex engaging pieces, the first convex engaging piece is provided flush with the ring-shaped elastic plate and the second convex engaging piece. Is provided so as to bulge outward in the axial direction in accordance with the lead angle of the screw with respect to the first convex engaging piece, and the third convex engaging piece is the second convex And it is provided so as to further bulge outward in the axial direction in accordance with the lead angle of the screw relative to the engaging piece.

本願の請求項１記載の考案は、請求項１記載の構成において第１〜第３凸状係合片の平面視における各中心角をほぼ９０°とし、第１〜第３凹状切欠部の平面視における各中心角をほぼ３０°としたことを特徴とする。 According to the first aspect of the present invention, in the configuration according to the first aspect, each central angle in a plan view of the first to third convex engagement pieces is approximately 90 °, and the plane of the first to third concave cutouts is formed. Each central angle in viewing is approximately 30 °.

本考案の緩み止めナットによれば、ナット本体の上端面にカシメ固定されるリング状弾性板の内周面に、半径方向内方に突出しかつその突出端がねじ孔の内径とほぼ同径の円弧状に形成された３個の第１〜第３凸状係合片と、内面がねじ孔の谷径よりも大径の円弧状に形成された３個の第１〜第３凹状切欠部とが交互に形成される一方、第１〜第３凸状係合片のうち、第１凸状係合片はリング状弾性板と面一状に設けられると共に、第２凸状係合片は第１凸状係合片に対しねじのリード角に合わせて軸方向外方に膨出するように設けられ、第３凸状係合片は第２凸状係合片に対しねじのリード角に合わせてさらに軸方向外方に膨出するように設けられて、これら第１〜第３凸状係合片が全体としてねじのリード角に合わせた立体形状に形成されているから、緩み止めナットのボルトへの螺入時、第１〜第３凸状係合片がボルトのねじ山の間にそれぞれ容易かつスムーズに入り込むことができ、しかも、３個の第１〜第３凸状係合片のうち、２個の凸状係合片に摩擦トルクが均等に発生し、安定した緩み止め機能を発揮することができる。さらに、ねじのリード角に合わせた立体形状の第１〜第３凸状係合片を有するリング状弾性板を採用することで、ボルトのねじ山に局部的に大きな応力がかかってねじ山を損傷させるといったことがなくなり、その結果、緩み止めナットをボルトから取り外した後に、これら緩み止めナット及びボルトを再び使用することが可能となり、再使用を行うことができる。 According to the locking nut of the present invention, the inner peripheral surface of the ring-shaped elastic plate that is caulked and fixed to the upper end surface of the nut main body protrudes radially inward and the protruding end has the same diameter as the inner diameter of the screw hole. Three first to third convex engagement pieces formed in an arc shape and three first to third concave cutout portions formed in an arc shape whose inner surface is larger than the valley diameter of the screw hole. Are formed alternately. Among the first to third convex engaging pieces, the first convex engaging piece is provided flush with the ring-shaped elastic plate, and the second convex engaging piece. Is provided so as to bulge outward in the axial direction in accordance with the lead angle of the screw with respect to the first convex engaging piece, and the third convex engaging piece is a screw lead with respect to the second convex engaging piece. The first to third convex engagement pieces are formed in a three-dimensional shape that matches the lead angle of the screw as a whole. Therefore, when the locking nut is screwed into the bolt, the first to third convex engaging pieces can easily and smoothly enter between the screw threads of the bolt, and the three first The friction torque is evenly generated in the two convex engaging pieces among the third convex engaging pieces, and a stable loosening prevention function can be exhibited. Further, by adopting a ring-shaped elastic plate having first to third convex engagement pieces having a three-dimensional shape that matches the lead angle of the screw, a large stress is locally applied to the thread of the bolt, and the thread is As a result, after the locking nut is removed from the bolt, the locking nut and the bolt can be used again and can be reused.

また、第１〜第３凸状係合片２１〜２３の平面視における各中心角をほぼ９０°とし、第１〜第３凹状切欠部２４〜２６の平面視における各中心角をほぼ３０°とすれば、つまり、第１〜第３凸状係合片の幅を第１〜第３凹状切欠部の幅よりも積極的に大きく設定すれば、従来のように凸状係合片と凹状切欠部とを等間隔で交互に配置する場合に比べて第１〜第３凸状係合片とボルトとの係合面積を増やすことができ、その結果、緩み止め効果をより確実に発揮させることができる。 Each central angle in the plan view of the first to third convex engagement pieces 21 to 23 is set to approximately 90 °, and each central angle in the plan view of the first to third concave cutout portions 24 to 26 is set to approximately 30 °. That is, if the width of the first to third convex engagement pieces is set to be positively larger than the width of the first to third concave cutouts, the convex engagement piece and the concave shape as in the conventional case. The engagement area between the first to third convex engagement pieces and the bolt can be increased as compared with the case where the notches are alternately arranged at equal intervals, and as a result, the effect of preventing loosening can be more reliably exhibited. be able to.

本考案に係る緩み止めナットの縦断面図である。It is a longitudinal cross-sectional view of the locking nut according to the present invention. 同ナットの平面図である。It is a top view of the nut. リング状弾性板の平面図である。It is a top view of a ring-shaped elastic board. 図３のＡ−Ａ断面図である。It is AA sectional drawing of FIG. 第１凸状係合片の螺入状態を示す縦断面図である。It is a longitudinal cross-sectional view which shows the screwing state of a 1st convex engagement piece. 第２凸状係合片の螺入状態を示す縦断面図である。It is a longitudinal cross-sectional view which shows the screwing state of a 2nd convex engagement piece. 第３凸状係合片の螺入状態を示す縦断面図である。It is a longitudinal cross-sectional view which shows the screwing state of a 3rd convex engagement piece.

以下本考案に係る緩み止めナットを図に基づいて説明する。 Hereinafter, a locking nut according to the present invention will be described with reference to the drawings.

図１及び図２は、本考案に係る緩み止めナットを示し、この緩み止めナットＮは、中心部に軸方向に貫通するねじ孔１ａが形成されたナット本体１と、このナット本体１の上面にカシメ止めされたリング状弾性板２とを備える。ナット本体１の上面には、ねじ孔１ａと同心でかつねじ孔１ａの谷径よりも大径の環状カシメ部１１が設けられており、また、ナット本体１の下部には、座部１２が設けられている。なお、ナット本体１の形状としては図２のように平面視六角形とするほか、たとえば四角形や八角形などの多角形或いは円筒形であってもよい。また、座部１２については特に設けなくてもよい。 1 and 2 show a locking nut according to the present invention. The locking nut N includes a nut body 1 having a screw hole 1a penetrating in the axial direction in the center, and an upper surface of the nut body 1. And a ring-shaped elastic plate 2 that is crimped to the ring. An annular caulking portion 11 that is concentric with the screw hole 1 a and larger in diameter than the valley diameter of the screw hole 1 a is provided on the upper surface of the nut body 1, and a seat portion 12 is provided at the lower portion of the nut body 1. Is provided. The shape of the nut body 1 may be a hexagonal shape in plan view as shown in FIG. 2, or may be a polygon such as a quadrangle or an octagon or a cylinder. Further, the seat portion 12 need not be provided.

リング状弾性板２は、図３及び図４に示すように金属製弾性板からなり、その内周面に、半径方向内方に突出しかつその突出端がねじ孔１ａの内径とほぼ同径の円弧状に形成された３個の第１〜第３凸状係合片２１〜２３と、内面がねじ孔１ａの谷径よりも大径の円弧状に形成された３個の第１〜第３凹状切欠部２４〜２６とが交互に形成されている。そして、第１〜第３凸状係合片２１〜２３のうち、第１凸状係合片２１はリング状弾性板２と面一状に設けられると共に、第２凸状係合片２２は第１凸状係合片２１（リング状弾性板２）に対しボルト３のねじのリード角に合わせて軸方向外方に膨出するように設けられ、第３凸状係合片２３は第２凸状係合片２２に対しねじのリード角に合わせてさらに軸方向外方に膨出するように設けられている。
また、第１〜第３凸状係合片２１〜２３と第１〜第３凹状切欠部２４〜２６とを交互に設けるに際し、第１〜第３凸状係合片２１〜２３の各中心角をほぼ９０°とし、第１〜第３凹状切欠部２４〜２６の各中心角をほぼ３０°とした間隔で交互に形成されている。さらに、各凸状係合片２１〜２３の内面はねじ孔１ａの内径とほぼ同径の円弧状に形成され、また、各切欠凹部２２…２２の内面はねじ孔１ａの谷径よりも大径の円弧状に形成されている。The ring-shaped elastic plate 2 is made of a metal elastic plate as shown in FIGS. 3 and 4, and protrudes radially inward on the inner peripheral surface thereof, and the protruding end thereof has substantially the same diameter as the inner diameter of the screw hole 1a. Three first to third convex engagement pieces 21 to 23 formed in an arc shape and three first to first projections formed in an arc shape whose inner surface is larger than the valley diameter of the screw hole 1a. Three concave notches 24 to 26 are alternately formed. Of the first to third convex engaging pieces 21 to 23, the first convex engaging piece 21 is provided flush with the ring-shaped elastic plate 2, and the second convex engaging piece 22 is The first convex engagement piece 21 (ring-shaped elastic plate 2) is provided so as to bulge outward in the axial direction in accordance with the lead angle of the bolt 3 and the third convex engagement piece 23 is The two convex engagement pieces 22 are provided so as to bulge outward in the axial direction in accordance with the lead angle of the screw.
Moreover, when providing the 1st-3rd convex engagement pieces 21-23 and the 1st-3rd concave notch parts 24-26 alternately, each center of the 1st-3rd convex engagement pieces 21-23 The angles are approximately 90 °, and the first to third concave cutouts 24 to 26 are alternately formed at intervals of approximately 30 °. Furthermore, the inner surfaces of the convex engagement pieces 21 to 23 are formed in an arc shape having substantially the same diameter as the inner diameter of the screw hole 1a, and the inner surfaces of the notch recesses 22 ... 22 are larger than the valley diameter of the screw hole 1a. It is formed in a circular arc shape with a diameter.

そして、このリング状弾性板２は、環状カシメ部１１の内部に、ねじ孔１ａと同心で水平状にカシメ固定されている。 The ring-shaped elastic plate 2 is caulked and fixed in a horizontal manner concentrically with the screw hole 1 a inside the annular caulking portion 11.

具体的には、リング状弾性板２をナット本体１の上面にカシメ固定する際、予めナット本体１の上端面に、ねじ孔１ａと同心にざぐり穴（図示せず）を形成し、このざぐり穴の底面にリング状弾性板２をねじ孔１ａと同心で水平に位置決め載置した後、ざぐり穴の周壁を内側にカシメることによりリング状弾性板２をざぐり穴の底面にカシメ固定している。 Specifically, when the ring-shaped elastic plate 2 is caulked and fixed to the upper surface of the nut main body 1, a counterbore (not shown) is formed in the upper end surface of the nut main body 1 concentrically with the screw hole 1a in advance. After the ring-shaped elastic plate 2 is positioned and placed concentrically with the screw hole 1a on the bottom surface of the hole, the ring-shaped elastic plate 2 is crimped and fixed to the bottom surface of the counterbore hole by crimping the peripheral wall of the counterbore hole inward. Yes.

次に、この緩み止めナットの使用状態について説明する。 Next, the use state of this locking nut will be described.

使用時には、図５〜図７に示すように通常どおり緩み止めナットＮをボルト３に螺入して、被締付物（図示せず）を締め付ける。この際、緩み止めナットＮの上面には、ねじのリード角に合わせた立体形状の第１〜第３凸状係合片２１〜２３を有するリング状弾性板２がカシメ固定されているので、まず、図５に示すように、ボルト３のねじ山３ａの切上がりをリング状弾性板２の第１切欠凹部２４の隙間から第１凸状係合片２１に入り込ませて螺入させる。次に、引き続き緩み止めナットＮをボルト３に螺入することにより、図６に示すようにボルト３のねじ山３ａの切上がりを、リング状弾性板２の第２切欠凹部２５の隙間から第２凸状係合片２２に容易に入り込ませて螺入させる。さらに、緩み止めナットＮをボルト３に螺入することにより、図７に示すようにボルト３のねじ山３ａを、第２切欠凹部２５の隙間から第２凸状係合片２３に容易に入り込ませて螺入させるのである。 At the time of use, as shown in FIG. 5 to FIG. 7, the locking nut N is screwed into the bolt 3 as usual, and an object to be tightened (not shown) is tightened. At this time, since the ring-shaped elastic plate 2 having the first to third convex engagement pieces 21 to 23 having a three-dimensional shape that matches the lead angle of the screw is caulked and fixed to the upper surface of the locking nut N, First, as shown in FIG. 5, the thread 3 a of the bolt 3 is cut into the first convex engagement piece 21 from the gap of the first cutout recess 24 of the ring-shaped elastic plate 2 and screwed into the first convex engagement piece 21. Next, by continuously screwing the locking nut N into the bolt 3, the thread 3 a of the bolt 3 is lifted up from the gap of the second notch recess 25 of the ring-shaped elastic plate 2 as shown in FIG. 6. The two convex engaging pieces 22 are easily inserted and screwed. Further, by screwing the locking nut N into the bolt 3, as shown in FIG. 7, the thread 3a of the bolt 3 easily enters the second convex engagement piece 23 from the gap of the second notch recess 25. And screw it in.

その場合、リング状弾性板２における第１凸状係合片２１はリング状弾性板２と面一状に設けられると共に、第２凸状係合片２２は第１凸状係合片２１（リング状弾性板２）に対しボルト３のねじのリード角に合わせて軸方向外方に膨出するように設けられ、第３凸状係合片２３は第２凸状係合片２２に対しねじのリード角に合わせてさらに軸方向外方に膨出するように設けられて、これら第１〜第３凸状係合片が全体としてねじのリード角に合わせた立体形状に形成されているから、第１〜第３凸状係合片２１〜２３がボルト３のねじ山３ａの間に容易かつスムーズに入り込むことができると共に、３個の第１〜第３凸状係合片２１〜２３のうち、摩擦トルクが２個の凸状係合片に均等に発生し、安定した緩み止め機能を発揮することができる。 In that case, the first convex engagement piece 21 in the ring-shaped elastic plate 2 is provided flush with the ring-shaped elastic plate 2, and the second convex engagement piece 22 is the first convex engagement piece 21 ( The ring-shaped elastic plate 2) is provided so as to bulge outward in the axial direction in accordance with the lead angle of the screw of the bolt 3, and the third convex engagement piece 23 is relative to the second convex engagement piece 22. The first to third convex engaging pieces are formed in a three-dimensional shape that matches the lead angle of the screw as a whole, provided so as to bulge outward in the axial direction according to the lead angle of the screw. Thus, the first to third convex engaging pieces 21 to 23 can easily and smoothly enter between the screw threads 3a of the bolt 3, and the three first to third convex engaging pieces 21 to 21 can be inserted. 23, the friction torque is evenly generated in the two convex engaging pieces, and a stable locking function can be exhibited. That.

しかも、ねじのリード角に合わせた立体形状の第１〜第３凸状係合片２１〜２３を有するリング状弾性板２を採用することで、ボルト３のねじ山３ａに局部的に大きな応力がかかってねじ山３ａを損傷させるといったことがほとんどなくなり、その結果、緩み止めナットＮをボルト３から取り外した後に、これら緩み止めナットＮ及びボルト３を再び使用することが可能となり、再使用を行うことができる。 Moreover, by adopting the ring-shaped elastic plate 2 having the first to third convex engagement pieces 21 to 23 having a three-dimensional shape that matches the lead angle of the screw, a large stress is locally applied to the thread 3a of the bolt 3. As a result, it is possible to use the locking nut N and the bolt 3 again after removing the locking nut N from the bolt 3, and to reuse them. It can be carried out.

また、第１〜第３凸状係合片２１〜２３の平面視における各中心角をほぼ９０°とし、第１〜第３凹状切欠部２４〜２６の平面視における各中心角をほぼ３０°としているので、つまり、第１〜第３凸状係合片２１〜２３の幅を第１〜第３凹状切欠部２４〜２６の幅よりも積極的に大きく設定しているので、従来のように第１〜第３凸状係合片と第１〜第３凹状切欠部とを等間隔で交互に配置する場合に比べて第１〜第３凸状係合片とボルトとの係合面積を増やすことができ、その結果、緩み止め効果をより確実に発揮させることができる。 Each central angle in the plan view of the first to third convex engagement pieces 21 to 23 is set to approximately 90 °, and each central angle in the plan view of the first to third concave cutout portions 24 to 26 is set to approximately 30 °. That is, since the width of the first to third convex engagement pieces 21 to 23 is set to be positively larger than the width of the first to third concave cutout portions 24 to 26, Compared to the case where the first to third convex engagement pieces and the first to third concave cutouts are alternately arranged at equal intervals, the engagement area between the first to third convex engagement pieces and the bolt As a result, the loosening prevention effect can be more reliably exhibited.

Ｎ緩み止めナット
１ナット本体
１ａねじ孔
１１環状カシメ部
２リング状弾性板
２１凸状係合片
２２凸状係合片
２３凸状係合片
２４凹状切欠部
２５凹状切欠部
２６凹状切欠部N Locking nut 1 Nut body 1a Screw hole 11 Ring caulking portion 2 Ring-shaped elastic plate 21 Convex engagement piece 22 Convex engagement piece 23 Convex engagement piece 24 Concave notch 25 Concave notch 26 Concave notch

Claims

中心部に軸方向に貫通するねじ孔が形成されたナット本体の上端面に環状カシメ部が設けられ、そのカシメ部の内部にねじ孔と同心で水平状に緩み止め用のリング状弾性板がカシメ固定された緩み止めナットにおいて、リング状弾性板の内周面に、半径方向内方に突出しかつその突出端がねじ孔の内径とほぼ同径の円弧状に形成された３個の第１〜第３凸状係合片と、内面がねじ孔の谷径よりも大径の円弧状に形成された３個の第１〜第３凹状切欠部とが交互に形成されている一方、第１〜第３凸状係合片のうち、第１凸状係合片はリング状弾性板と面一状に設けられると共に、第２凸状係合片は第１凸状係合片に対しねじのリード角に合わせて軸方向外方に膨出するように設けられ、第３凸状係合片は第２凸状係合片に対しねじのリード角に合わせてさらに軸方向外方に膨出するように設けられていることを特徴とする緩み止めナット。 An annular caulking portion is provided on the upper end surface of the nut body in which a screw hole penetrating in the axial direction is formed in the center portion, and a ring-shaped elastic plate for preventing loosening in a horizontal manner is concentric with the screw hole inside the caulking portion. In the caulking-fixed locking nut, three first pieces are formed on the inner peripheral surface of the ring-shaped elastic plate so as to project radially inward and whose projecting ends are formed in an arc shape having substantially the same diameter as the inner diameter of the screw hole. While the third convex engagement pieces and the three first to third concave cutouts whose inner surface is formed in an arc shape having a diameter larger than the valley diameter of the screw hole are alternately formed, Among the first to third convex engaging pieces, the first convex engaging piece is provided flush with the ring-shaped elastic plate, and the second convex engaging piece is in relation to the first convex engaging piece. The third convex engagement piece is provided so as to bulge outward in the axial direction in accordance with the lead angle of the screw, and the lead angle of the screw with respect to the second convex engagement piece Locking nut, characterized in that provided as further bulging axially outward combined.

第１〜第３凸状係合片の平面視における各中心角をほぼ９０°とし、第１〜第３凹状切欠部の平面視における各中心角をほぼ３０°としたことを特徴とする請求項１記載の緩み止めナット。 Each central angle in a plan view of the first to third convex engaging pieces is approximately 90 °, and each central angle in a plan view of the first to third concave cutout portions is approximately 30 °. The locking nut according to Item 1.