JP3163716U - Fastening structure for locking nut, bolt and nut - Google Patents

Abstract

To improve a conventional locking nut in which an elastic body is attached to a free surface on the trailing side of a nut body, and to provide a locking structure of a locking nut and a bolt / nut that can exhibit a more effective locking action. Offer. A nut body 21 and a loosening-preventing elastic body 31 attached to the nut body 21 are provided. The elastic body 31 includes an engagement piece projecting into the screw hole. The engagement piece exerts a locking action by engaging with the male screw 22 of the bolt 11 screwed into the screw hole and elastically deforming. A screw-free cylindrical portion 23 is formed on the seating surface side of the screw hole of the nut main body 21, and the cylindrical portion 23 allows the axial force of the bolt 11 generated during tightening and the elastic force of the elastic body 31 to be nuts. It is dispersed on the outer peripheral side of the seating surface 24. [Selection] Figure 1

Description

  The present invention relates to a fastening structure for a locking nut and a bolt / nut.

  The inventor of the present application has provided a locking nut with an elastic body attached to the free surface on the trailing side of the nut body as shown in Patent Documents 1 and 2 for many years. The locking nut includes an engagement piece in which the elastic body protrudes into the screw hole, and the engagement piece engages with a male screw of a bolt that is screwed into the screw hole to move away from the free surface. By elastically deforming in the direction, an elastic force in the axial direction is applied to the male screw to exert a locking action.

Japanese Utility Model Publication No. 06-35637 No. 7-40724

  The present invention is an improvement of a conventional locking nut in which an elastic body is attached to a free surface on the trailing side of the nut body, and a fastening structure of a locking nut and a bolt / nut that can exhibit a more effective locking function. Is intended to provide.

The invention according to claim 1 of the present application is a locking nut including a nut body having a screw hole in the center, and an elastic body for locking that is attached to the nut body.
The elastic body is attached to the free surface on the trailing side of the nut body,
The elastic body includes an engagement piece projecting into the screw hole,
The engaging piece engages with a male screw of a bolt that is screwed into the screw hole and elastically deforms in a direction away from the free surface, thereby exerting an axial elastic force on the male screw and exerting a locking action. Is,
A screwless cylindrical portion is formed on the seating surface side of the screw hole, and this cylindrical portion disperses the axial force of the bolt and the elastic force generated during tightening on the outer peripheral side of the seating surface. A locking nut is provided.

  In the invention according to claim 2 of the present application, the cylindrical portion has a diameter of 0 to 1.0 mm added to the root diameter of the screw hole, and the height is 1.5 to 1.5 of the female screw. The loosening prevention nut according to claim 1, characterized in that it is for three pitches.

  The invention according to claim 3 of the present application provides the locking nut according to claim 1 or 2, wherein the nut is a hexagonal nut having an outer periphery having the same shape and size in the axial direction. .

  In the invention according to claim 4 of the present application, the nut has a hexagonal prism shape in which the outer periphery on the free end side has the same shape and size in the axial direction, and the outer periphery on the seat surface side gradually approaches the seat surface side. The loosening prevention nut according to claim 1 or 2, characterized by being a skirt hexagonal nut which becomes larger.

  The invention according to claim 5 of the present application provides a bolt / nut fastening structure comprising the locking nut according to any one of claims 1 to 4 and a bolt screwed into the screw hole.

  In the present invention, when the elastic force of the elastic body acts on the seat surface of the nut in addition to the axial force of the bolt generated at the time of tightening the bolt and nut, a screwless cylindrical portion is formed on the seat surface side. Thus, the resultant force of the axial force of the bolt and the elastic force of the elastic body can be dispersed on the outer peripheral side of the seat surface.

  In this way, as a result of the pressure being distributed to the outer peripheral side away from the threaded male screw and female screw, the force is uniformly distributed on the outer peripheral side away from the screw structure, and is substantially uniform over the entire seating surface. Acts on the object to be fastened. Thereby, the prevention effect of a loosening prevention is exhibited more effectively than the fastening structure provided with the conventional elastic body.

Sectional drawing of the fastening structure of the volt | bolt and nut which concerns on one embodiment of this invention device. The nut which concerns on the same embodiment is shown, (A) is a top view, (B) is a front view. The top view of the elastic body with which the nut which concerns on the same embodiment was mounted | worn. Sectional drawing of the fastening structure of the volt | bolt and nut which concerns on other embodiment of this invention device. The nut which concerns on the same embodiment is shown, (A) is a top view, (B) is a front view.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

The bolt / nut fastening structure of this embodiment is a structure in which the shaft portion 12 of the bolt 11 and the nut 20 are screwed together, and the fastened object 41 is the head 14 of the bolt 11 and the seating surface 24 of the nut 20. When the bolt 11 and the nut body 21 are tightened, an axial force is generated and the bolt and nut are fastened. Although the shapes of the bolt 11 and the nut body 21 can be changed as appropriate, hexagonal bolts and nuts are employed in this example.
The bolt 11 can be a normal bolt, and includes a shaft portion 12 provided with a male screw 13 and a head portion 14 provided at an end portion of the shaft portion 12 as necessary.
The nut 20 includes a nut main body 21 and an elastic body 31 attached to the nut main body 21.

  The nut body 21 has a screw hole in the center, and includes a seating surface 24 in the lower part of the figure. An internal thread 22 is formed in the screw hole, and a non-threaded cylindrical portion 23 is formed on the seating surface 24 side. The inner diameter of the cylindrical portion 23 is preferably about 0 to 1.0 mm added to the root diameter of the female screw 22, and more preferably about 0 to 0.5 mm added to the nominal diameter of the male screw 13 of the bolt 11. Moreover, it is preferable that the height (axial length) of the cylindrical part 23 is 1.5-3 pitches of the external thread 13 from the seat surface 24. FIG.

  An elastic body 31 is attached to the free end surface (upper surface in the figure) opposite to the seat surface 24 of the nut body 21. As shown in FIG. 3, the elastic body 31 has an annular thin plate shape in plan view, and is made of an elastic metal such as spring steel. The elastic body 31 is fixed by caulking by the caulking portion 25 of the nut body 21 with the outer peripheral side serving as a fixing portion 32. An appropriate number (two pieces in this example) of engagement pieces 33 protrudes in the radially inward direction on the inner peripheral side. The inner diameter of the engagement piece 33 is preferably equal to or slightly larger than the crest diameter of the female screw 22, but needs to be smaller than the trough diameter of the female screw 22.

  When the bolts and nuts are fastened, an axial force is generated by fastening the bolts 11 and the nut body 21 to the fastened object 41. Further, the elastic body 31 engages with the male screw 13 and elastically deforms, whereby the elastic force is applied to the nut body 21 in the axial direction. These axial force and elastic force are applied to the fastened object 41 from the seating surface 24, but these forces are dispersed on the outer peripheral side of the seating surface 24 by forming the cylindrical portion 23. . Thus, as a result of the pressure being distributed to the outer peripheral side away from the screwing of the helical male screw 13 and the female screw 22, the force is uniformly distributed on the outer peripheral side away from the screw structure, and the seat surface 24 It acts on the fastened object 41 substantially uniformly as a whole. Thereby, the effect of preventing the loosening is more effectively exhibited than the fastening structure provided with the conventional elastic body 31.

Next, FIGS. 4 and 5 show another embodiment. The nut body 21 of the nut 20 according to this embodiment has a hexagonal column shape in which the outer periphery on the free end side (upper side) has the same shape and size in the axial direction, and the outer periphery of the seating surface 24 is on the seating surface side. The skirt hexagon nut is provided with a skirt skirt portion 26 that gradually increases as it goes. Other structures are the same as in the previous example. In the previous example, the area of the seating surface 24 is reduced by the provision of the cylindrical portion 23. However, in this example, the area of the seating surface 24 is increased by providing the skirt portion 26, and the loosening is more effectively prevented. The effect can be exhibited.
In addition to the above-described embodiment, the present invention can be implemented with various modifications. For example, the number of locking pieces 32 of the elastic body 31 is not limited to two, and may be one or three or more. The screw may be a double thread. The cross-sectional shape of the nut main body 21 is not limited to a hexagon, but may be another polygon such as a quadrangle, or an ellipse or a circle depending on circumstances.

11 Bolt 12 Shaft portion 13 Male screw 14 Head 20 Nut 21 Nut body 22 Female screw 23 Cylindrical portion 24 Seat surface 25 Caulking portion 26 Skirt portion 31 Elastic body 32 Fixing portion 33 Engagement piece 41 Fastened object

Claims (5)

In the nut main body having a screw hole in the center, and a locking nut provided with an elastic body for locking to the nut attached to the nut main body,
The elastic body is attached to the free surface on the trailing side of the nut body,
The elastic body includes an engagement piece projecting into the screw hole,
The engaging piece engages with a male screw of a bolt that is screwed into the screw hole and elastically deforms in a direction away from the free surface, thereby exerting an axial elastic force on the male screw and exerting a locking action. Is,
A screwless cylindrical portion is formed on the seating surface side of the screw hole, and this cylindrical portion disperses the axial force of the bolt and the elastic force generated during tightening on the outer peripheral side of the seating surface. A locking nut characterized by being. The cylindrical portion has a diameter obtained by adding 0 to 1.0 mm to the root diameter of the screw hole, and the height is 1.5 to 3 pitches of the female screw. The locking nut according to claim 1. The loosening prevention nut according to claim 1 or 2, wherein the nut is a hexagonal nut whose outer periphery has the same shape and size in the axial direction. The nut is a skirt hexagon nut whose outer periphery on the free end side is a hexagonal column having the same shape and size in the axial direction, and the outer periphery on the seat surface side gradually increases toward the seat surface side. The loosening prevention nut according to claim 1 or 2 characterized by things. A bolt-nut fastening structure comprising the locking nut according to any one of claims 1 to 4 and a bolt screwed into the screw hole.

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