JP3164885U - Locking nut - Google Patents

Abstract

The 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

  The present invention relates to a locking nut.

  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.

  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.

  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.

  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.

  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.

  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 °.

  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.

  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.

It is a longitudinal cross-sectional view of the locking nut according to the present invention. It is a top view of the nut. It is a top view of a ring-shaped elastic board. It is AA sectional drawing of FIG. It is a longitudinal cross-sectional view which shows the screwing state of a 1st convex engagement piece. It is a longitudinal cross-sectional view which shows the screwing state of a 2nd convex engagement piece. It is a longitudinal cross-sectional view which shows the screwing state of a 3rd convex engagement piece.

  Hereinafter, a locking nut according to the present invention will be described with reference to the drawings.

  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.

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.

  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.

  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.

  Next, the use state of this locking nut will be described.

  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.

  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.

  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.

  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 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 (2)

  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.   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.

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