JP2019015392A - Looseness prevention nut - Google Patents

Abstract

To provide a looseness prevention nut excellent in fastening workability.SOLUTION: A looseness prevention nut comprises two nuts 1, 1' with the same shape, each nut 1, 1' has a projection part 10 (10') and a recess part 20, with an upper surface 2 orthogonal to an axis as reference, wherein the projection part 10' of one nut 1' is fitted into the recess part 20 of the other nut 1 to retighten them. The projection part 10 is formed in a part of a region around a screw hole 30 and formed into an arc shape, and the recess part 20 is formed in a part of the region around the screw hole 30 and formed into an arc shape. A width of one end surface 13 of the projection part 10 is narrower than a width of the other end surface 12 of the projection part 10, and a width of the recess part 20 into which the end surface 13 is fitted is narrower than a width of the recess part 20 into which the end surface 12 is fitted.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a locking nut.

  As a conventional locking nut, for example, a locking nut comprising an upper nut and a lower nut, the upper nut has a contact portion that comes into contact with the lower end of a tightening tool such as a spanner during the tightening operation of the upper nut. Has been proposed, and the abutting portion is provided, for example, so as to protrude from a part of the outer periphery of the upper nut so that the rotation amount of the upper nut can be visually recognized (for example, Patent Documents). 1).

  However, since the upper nut and the lower nut are different in the shape described in Patent Document 1, the upper nut and the lower nut cannot be tightened at the same time, the tightening efficiency is poor, and the tightening workability is poor. There is.

JP 2002-195236 A

  In view of the above problems, the present invention provides a locking nut excellent in tightening workability.

  The locking nut according to one aspect of the present invention includes two nuts having the same shape, and each nut has a convex portion and a concave portion with respect to an upper surface orthogonal to the shaft, and the convex portion of one nut is the other. A locking nut that is fitted into a recess of the nut and tightened further, wherein the protrusion has an arc shape formed in a part of the area around the screw hole, and the recess is a part of the periphery of the screw hole. The width of one end surface of the convex portion is narrower than the width of the other end surface of the convex portion, and the width of the concave portion into which the one end surface is fitted is the other width. It is characterized in that the end face is narrower than the width of the concave part to be fitted.

  The locking nut according to one embodiment of the present invention is excellent in tightening workability.

(A) is a side view of one nut of the locking nut according to the embodiment of the present invention, (b) is a plan view of one nut of the locking nut according to the embodiment of the present invention, (c) is The top view for demonstrating the fitting state at the time of overlapping the other nut on the one nut which concerns on one Embodiment of this invention, (d) is one nut of the locking nut which concerns on one Embodiment of this invention. It is a perspective view. (A) is a side view showing a state in the middle of tightening of the locking nut according to one embodiment of the present invention, (b) is a side view showing a state after retightening of the locking nut according to one embodiment of the present invention. (Partially cutaway view).

<Overview>
The locking nut according to one aspect of the present invention includes two nuts having the same shape, and each nut has a convex portion and a concave portion with respect to an upper surface orthogonal to the shaft, and the convex portion of one nut is the other. A locking nut that is fitted into a recess of the nut and tightened further, wherein the protrusion has an arc shape formed in a part of the area around the screw hole, and the recess is a part of the periphery of the screw hole. The width of one end surface of the convex portion is narrower than the width of the other end surface of the convex portion, and the width of the concave portion into which the one end surface is fitted is the other width. It is characterized by being narrower than the width | variety of the said recessed part into which an end surface of this fits.

  According to this embodiment, the two nuts have the same shape, and when the top surfaces of the nuts are inverted 180 degrees with respect to the center line and the top surfaces of the two nuts are overlapped, the convex portion of one nut Fits into the recess of the other nut. Therefore, two nuts can be simultaneously tightened with a tightening tool, and the tightening workability is excellent.

  Further, when the two nuts are tightened at the same time and the upper nut is tightened at the end, the convex portion bites into the concave portion, and the occurrence of loosening can be suppressed by the so-called wedge effect.

  In the present embodiment, the two nuts have the same shape, and both can be used as an upper nut or a lower nut. Therefore, the number of parts is small, and parts management is easy.

<Embodiment>
Hereinafter, a locking nut which is an embodiment of the present invention will be described in detail with reference to the drawings.

  1A is a side view of the nut 1, FIG. 1B is a plan view of the nut 1, and FIG. 1C is a diagram illustrating a fitting state when the other nut 1 ′ (see FIG. 2) is stacked on the nut 1. FIG. 3D is a perspective view of the nut 1.

  FIG. 2A is a side view showing a state in the middle of tightening of the locking nut of the present embodiment, and FIG. 2B is a side view showing a state after the tightening of the locking nut of the present embodiment (partial). It is a cutaway view).

  In FIG.2 (b), 50 shows a fastening body. Examples of the fastening body include a thin steel plate and a member (H steel, L steel, etc.) thicker than the steel plate.

1. Nut The locking nut of the present embodiment is a combination of a nut 1 and a nut 1 ′. Here, the nut 1 and the nut 1 ′ have the same shape, and when it is not necessary to distinguish between them, the nut 1 is simply indicated as the nut 1.

  The shape of the nut 1 used in the present embodiment is not particularly limited, but in the embodiment, a hexagonal nut having a chamfered lower surface 3 is used.

  The nut 1 has an arc-shaped convex portion 10 that protrudes upward in the axial direction with respect to the upper surface 2 that is orthogonal to the axis, and an arc-shaped concave portion 20 that is recessed downward in the axial direction with respect to the upper surface 2 that is orthogonal to the axis. .

  Although details will be described later, the convex portion 10 of one nut is fitted into the concave portion 20 of the other nut.

2. Screw hole A screw hole 30 having a concentric outer peripheral surface 31 with respect to the shaft core P (the center point of the screw hole) and penetrating through the shaft center is formed at the center of the nut 1.

3. Convex part, Concave part Convex part 10 is formed in a part of the periphery of outer peripheral surface 31 of screw hole 30, and has an arc shape having tapered outer peripheral surface 11 whose diameter decreases in the axial direction upward.

  The end surfaces 12 and 13 of the convex portion 10 have a trapezoidal shape in which the upper surface is slightly smaller than the bottom surface (lower surface) as the outer peripheral surface 11 is reduced in diameter. Here, the end surfaces 12 and 13 refer to end surfaces orthogonal to the circumferential direction of the convex portion 10.

  In addition, the internal thread 41 is cut by the inner peripheral surface (surface facing the outer peripheral surface 11) of the convex part 10 so that the volt | bolt 40 (refer FIG. 2) may be screwed together.

  The recess 20 is formed in a part of the periphery of the outer peripheral surface 31 of the screw hole 30 and has a circular arc shape having a tapered outer peripheral surface 21 whose diameter increases in the axial direction.

  The outer peripheral surface 11 of the convex portion 10 and the outer peripheral surface 21 of the concave portion 20 are on the same circle with Q as the center point.

  Here, Q is slightly decentered radially outward (upper side in the drawing) with respect to the axis P. Thus, since Q is eccentric, the width (lateral width) of the end surface 13 of the convex portion 10 is slightly narrower than the width (lateral width) of the end surface 12.

  The width (horizontal width) of the end surfaces 12 and 13 of the convex portion 10 may be either the width of the trapezoidal upper surface or the width of the bottom surface (lower surface), but here the width of the bottom surface (lower surface).

  Further, the width (horizontal width) of the virtual end surface 23 of the concave portion 20 into which the end surface 13 of the convex portion 10 is fitted is slightly narrower than the width (horizontal width) of the end surface 22 of the concave portion 20 into which the end surface 12 of the convex portion 10 is fitted. .

  Further, the width (horizontal width) of the end surface 24 of the concave portion 20 into which the end surface 13 of the convex portion 10 is fitted at the time of tightening is the same as the width (horizontal width) of the virtual end surface 23.

  The end surfaces 22, 23, 24 of the recess 20 have an inverted trapezoidal shape in which the upper surface is slightly larger than the bottom surface (lower surface) as the outer peripheral surface 21 is enlarged.

  The width (lateral width) of the end faces 22, 23, 24 of the recess 20 may be either the width of the upper surface of the inverted trapezoidal shape or the width of the bottom surface (lower surface), but here it refers to the width of the upper surface.

  The height of the convex portion 10 and the depth of the concave portion 20 are the same. Thereby, the convex part 10 fits into the concave part 20. The height of the convex portion 10 varies depending on the thickness of the nut 1, but is preferably in the range of 1/2 to 1/4 of the thickness of the nut 1.

  The taper angle of the outer peripheral surface 11 of the convex portion 10 and the taper angle of the outer peripheral surface 21 of the concave portion 20 are the same. Thereby, the convex part 10 becomes easy to fit into the concave part 20, and the wedge effect is obtained more. There is no particular limitation on the taper angle.

  As shown in FIG. 1B, the arc-shaped convex portion 10 is formed in a region corresponding to 150 degrees of the entire circumference of the outer peripheral surface 31 of the screw hole 30, and the arc-shaped concave portion 20 It is formed in a region corresponding to 210 degrees of the entire circumference of 30 outer peripheral surfaces 31. When the region of the convex portion 10 and the region of the concave portion 20 are combined, it corresponds to the entire circumference (360 degrees) of the outer peripheral surface 31 of the screw hole 30.

  Here, since the recessed part 20 has a tightening area | region (area | region corresponding to 23 to 24 of FIG.1 (b)), it is larger than the convex part 10 by that much.

  When the convex portion 10 becomes larger than a region corresponding to 180 degrees of the entire circumference of the outer peripheral surface 31, the region of the concave portion 20 becomes smaller than 180 degrees. Therefore, when the two nuts 1 are overlapped, the convex portion 10 is formed. It will not fit in the recess 20. Therefore, the convex part 10 needs to be formed in the area | region equivalent to less than 180 degree | times of the perimeter of the outer peripheral surface 31. FIG.

4). Procedure for tightening the locking nut As shown in FIG. 2A, when the nut 1 'is inverted 180 degrees on the upper surface 2 of the nut 1 and the upper surfaces 2 are overlapped with each other, the convex portion 10' of the other nut 1 ' Is fitted into the recess 20 of the nut 1 (portion indicated by a vertical line in FIG. 1C). Here, since the size of the convex portion 10 ′ is substantially the same as the size of the portion indicated by the vertical line of the concave portion 20, the convex portion 10 ′ fits into the concave portion 20 without any resistance. Reference numerals 12 'and 13' denote end faces of the convex portion 10 '. The width of the end face 13 'is slightly narrower than the width of the end face 12'.

  As shown in FIG. 2 (a), the two nuts 1 and 1 'are overlapped and screwed onto the tip of the bolt 40. Here, the corners of the lower nut 1 and the upper nut 1 ′ are overlapped without being shifted. That is, the six side surfaces of the lower nut 1 and the six side surfaces of the upper nut 1 ′ overlap with each other without being displaced. Therefore, the two superimposed nuts 1 and 1 ′ can be simultaneously tightened with a tightening tool.

  Tighten until the lower surface 3 of the lower nut 1 contacts the fastening body 50 (see FIG. 2B). Finally, when the upper nut 1 'is rotated by about one angle (about 60 °) of the hexagon nut and tightened (see FIG. 2 (b)), the end faces 12' and 13 'of the convex portion 10' After moving to 12 ″ and 13 ″ (the portion indicated by the oblique lines in FIG. 1C), the convex portion 10 ′ of the other nut 1 ′ bites into the concave portion 20 of the nut 1 and is tightened. Here, since the width of the end surface 12 ″ is slightly narrower than the width of the end surface 12 ′, the convex portion 10 ′ bites into the concave portion 20 due to the wedge effect at the time of tightening, and the occurrence of loosening of the nut 1 can be suppressed.

5. Tightening tool The fastening tool used in the embodiment is not particularly limited, and examples thereof include a hexagon socket, a ratchet wrench, a torque wrench, and a spanner. Among these, a tool capable of simultaneously tightening the two superimposed nuts 1 is preferable (except during retightening).

<Modification>
As described above, the locking nut according to the embodiment has been described. However, the present invention is not limited to this embodiment, and for example, the following modification may be used. Further, the present invention may be a combination of the embodiment, the modified examples, and the modified examples.

  In addition, examples that are not described in the embodiments and modifications and design changes that do not depart from the gist are also included in the present invention.

1. Nut The locking nut of the present embodiment is composed of two nuts 1 and 1 'having the same shape, but when the upper surfaces 2 of the two nuts 1 and 1' are overlapped, one nut 1 ' The convex portion 10 ′ only needs to have a shape that fits into the concave portion 20 of the other nut 1, and the thickness of the nut may be slightly different.

  Further, the shape of the nut is not limited to a hexagon nut, and for example, a polygonal nut such as an octagonal nut, a round nut or the like may be used.

2. Convex part, concave part The shape of the convex part 10 and the concave part 20 is not limited to an arc shape. Moreover, the magnitude | size of the convex part 10 and the recessed part 20 is not limited to embodiment. However, since the concave portion 20 has a tightening region (region corresponding to 23 to 24 in FIG. 1B), it is necessary to make it larger than the convex portion 10. The outer peripheral surface of the convex portion and the outer peripheral surface of the concave portion are tapered, but may not be tapered.

3. Distance between P and Q The distance between P and Q (also referred to as eccentricity) can be changed as appropriate according to the size of the nut. In the case of a small nut, the eccentricity is small and is 1.0 mm or less, preferably 0. In the case of a large nut, the amount of eccentricity may be slightly increased.

  The locking nut according to the present embodiment is used for fastening steel plates and members used in an environment where vibration is applied, such as steel plates and members used in construction, vehicles (automobiles, etc.), ships, aircrafts, etc. Can be widely used for fastening.

DESCRIPTION OF SYMBOLS 1 Nut 1 'Nut 2 Upper surface 10 Convex part 10' Convex part 11 Outer peripheral surface 12 End surface 13 End surface 20 Concave part 30 Screw hole

Claims (4)

Consists of two nuts of the same shape, each nut having a convex part and a concave part on the basis of the upper surface orthogonal to the axis, and the convex part of one nut is fitted into the concave part of the other nut and tightened A locking nut,
The convex portion has an arc shape formed in a partial region around the screw hole, and the concave portion has an arc shape formed in a partial region around the screw hole,
The width of one end surface of the convex portion is narrower than the width of the other end surface of the convex portion,
A locking nut according to claim 1, wherein a width of the recess into which the one end surface is fitted is narrower than a width of the recess into which the other end surface is fitted. 2. The locking nut according to claim 1, wherein an outer peripheral surface of the convex portion and an outer peripheral surface of the concave portion are on the same circumference, and a center of the outer peripheral surface is slightly eccentric with respect to an axis of the screw hole. The outer peripheral surface of the convex portion has a tapered shape that decreases in diameter in the axially upward direction,
The loosening prevention nut according to claim 2, wherein the outer peripheral surface of the concave portion has a tapered shape whose diameter increases in the axial direction upward. The nut is a hexagonal nut. When the upper surfaces of the two nuts are overlapped with each other by reversing 180 degrees with respect to the upper surface of the nut, the side surfaces of the lower hex nut and the upper hex nut The loosening prevention nut according to any one of claims 1 to 3 which overlaps so that a side may become the same plane.

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