JPWO2017208401A1 - Loosening prevention nut and fastening method - Google Patents

Abstract

  More firmly prevent loosening due to the return rotation of the nut. The loosening prevention nut is continuous from the opening opened on one end surface, and is continuously connected from the female screw portion engaged with the male screw portion of the mating member, and the male screw portion of the mating member. And a hole having a diameter smaller than the outer diameter of the male screw and larger than the diameter of the male screw valley.

Description

  The present invention relates to a loosening prevention nut and a fastening method that are fastened to a mating member such as a bolt and prevent loosening due to return rotation caused by vibration or the like.

  Conventionally, bolts and nuts are used as fastening parts in order to fix various building members or machine parts. Bolts and nuts used as fastening parts may rotate in the return direction due to slippage due to vibration or rotation of the parts to be fastened. For this reason, loosening due to the rotation of the nut returns to the nut, and the reduction of the fastening effect becomes a problem.

  In order to prevent loosening due to this return rotation, various bolt and nut structures have been proposed (see Patent Documents 1 and 2).

  For example, in the technique described in Patent Document 1, when a nut is fastened to a bolt, the tip of a protrusion formed on the seat surface of the nut bites into the male screw portion of the bolt. And the protrusion which bite into the external thread part is crushed, and the loosening prevention effect is heightened by the raise of the frictional force wound in the external thread part of a bolt.

  Moreover, in the technique described in Patent Document 2, a part of the female screw portion of the nut is broken by the breaking portion of the male screw portion of the bolt. As a result, the nut screwed into the bolt is not loosened.

JP 11-315820 A JP-A-62-86409

  In the technique described in Patent Document 1, a part of the nut is deformed and contributes to an improvement in the frictional force with respect to the bolt to be screwed, thereby preventing loosening. However, improvement of frictional force has been used as a technique until it gets tired. For this reason, when the member to be fastened receives vibration or the member to be fastened rotates, it is not possible to prevent loosening due to return rotation due to slippage of the fastening part.

  In the technique described in Patent Document 2, the male screw portion of the bolt has a breaking portion, and loosening is prevented by breaking a part of the female screw portion of the nut. However, the bolt is not a structure that can improve the looseness of the nut having the male screw portion.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a loosening prevention nut and a fastening method that more firmly prevent loosening due to return rotation of the nut.

  The loosening prevention nut according to the present invention is continuous from an opening opened in one end surface, and is continuous from an internal thread portion screwed into a male screw portion of a mating member and an opening portion opened in the other end surface, And a hole having a diameter smaller than the outer diameter of the male screw of the member and larger than the diameter of the male screw.

  The fastening method according to the present invention includes a female screw portion that is continuous from an opening portion that is open to one end face, and is threaded into a male screw portion of a counterpart member, and is continuous from an opening portion that is open to the other end face. A loosening prevention nut having a diameter smaller than the male screw outer diameter of the male screw portion and larger than the male screw valley diameter from the female screw portion side with respect to the counterpart member When tightening and rotating with respect to the mating member to be attached and screwed, the thread of the male threaded portion of the mating member is plastically deformed in the hole.

  According to the loosening prevention nut and the fastening method according to the present invention, the loosening prevention nut provided with the female screw portion and the hole is attached to the mating member from the female screw portion side and screwed into the mating member. On the other hand, when tightening and rotating, the thread of the male screw portion of the mating member is plastically deformed at the hole portion. The plastically deformed male screw portion does not screw into the female screw portion of the loosening prevention nut. For this reason, the loosening prevention nut does not rotate in the backward direction of the plastically deformed male screw portion. Therefore, the loosening prevention nut can more firmly prevent loosening due to return rotation.

It is sectional drawing which shows the loosening prevention nut which concerns on Embodiment 1 of this invention. It is a figure which shows the state by which the loosening prevention nut which concerns on Embodiment 1 of this invention is fastened by a volt | bolt. It is a figure which shows the state which the internal thread part of the loosening prevention nut which concerns on Embodiment 1 of this invention screws together with the external thread part of a volt | bolt. It is a figure which shows the state which the hole of the loosening prevention nut which concerns on Embodiment 1 of this invention plastically deforms the external thread part of a volt | bolt. It is a partially expanded view which shows the external thread part of the volt | bolt which concerns on Embodiment 1 of this invention. It is a partially expanded view which shows the boundary which the external thread part of the volt | bolt which concerns on Embodiment 1 of this invention deformed plastically. It is sectional drawing which shows the loosening prevention nut which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, in each figure, what attached | subjected the same code | symbol is the same or it corresponds, and this is common in the whole text of a specification.
Furthermore, the forms of the constituent elements shown in the entire specification are merely examples and are not limited to these descriptions.

Embodiment 1 FIG.
A loosening prevention nut 100 according to Embodiment 1 of the present invention will be described.
FIG. 1 is a cross-sectional view showing a loosening prevention nut 100 according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing a state in which the loosening prevention nut 100 according to the first embodiment of the present invention is fastened to the bolt 40.
A loosening prevention nut 100 shown in FIG. 1 includes a female screw portion 20 and a hole portion 30.
The loosening prevention nut 100 has a general outer shape such as a hexagon, an octagon, or a tetragon.

  As shown in FIG. 2, the female screw portion 20 is continuous from an opening opened on one end surface 21 on the side attached to the bolt 40 that is a mating member, and is screwed into the male screw portion 41 of the bolt 40. The female thread portion 20 is formed with a thread 22 having a catching height according to a predetermined lead angle and pitch.

The hole portion 30 is continuous from the opening portion opened in the other end surface 31 opposite to the side attached to the bolt 40. The hole diameter of the hole portion 30 is smaller than the male screw outer diameter 42 of the male screw portion 41 of the bolt 40 and larger than the male screw valley diameter 43.
Specifically, the hole 30 is formed by plastically deforming the thread 44 of the male thread 41 of the bolt 40 so that the thread groove 45 of the male thread 41 of the bolt 40 is filled, and the male thread of the bolt 40 that becomes the outer peripheral surface 46. This is a hole diameter that configures the portion 41 to be larger than the inner diameter 23 of the female screw portion 20.
The hole diameter of the hole portion 30 is the same hole diameter dimension extending in the axial direction along the same center line.

  The female screw portion 20 and the hole portion 30 have the same center line extending in the axial direction. The female screw portion 20 and the hole portion 30 are formed directly and continuously inside the loosening prevention nut 100.

The loosening prevention nut 100 having the above-described configuration has a hole portion 30 continuous with the female screw portion 20 in a backward direction that is opposite to the tightening rotation direction. When the loosening prevention nut 100 is rotated in the tightening rotation direction, the hole 30 is plastically deformed so that the thread 44 of the male screw part 41 of the bolt 40 is crushed and does not screw with the female screw part 20 of the loosening prevention nut 100. Let
The loosening prevention nut 100 has a hole portion 30 continuous with the female screw portion 20. Therefore, when the loosening prevention nut 100 is rotated by the user in the tightening rotation direction using a jig, a large force is required for the hole 30 to plastically deform the thread 44 of the male thread 41 of the bolt 40. is there. However, when the user plastically deforms the thread 44 of the male threaded portion 41 of the bolt 40 with a great force, the plastically deformed portion of the male threaded portion 41 of the bolt 40 is difficult to deform again.

  FIG. 3 is a diagram showing a state in which the female thread portion of the loosening prevention nut according to Embodiment 1 of the present invention is screwed into the male thread portion of the bolt. FIG. 4 is a diagram illustrating a state in which the hole portion of the loosening prevention nut according to the first embodiment of the present invention plastically deforms the male screw portion of the bolt.

  First, as shown in FIG. 2, with respect to the bolt 40 having the male screw portion 41 that protrudes upward through the attachment hole 51 of the fastened member 50, the female opening at one end face 21 of the loosening prevention nut 100 is opened. The screw part 20 is screwed together.

  Next, the loosening prevention nut 100 is rotated in the tightening rotation direction by a user using a jig, and proceeds to the fastened member 50 side. As shown in FIG. 3, when the loosening prevention nut 100 is screwed into the bolt 40, the hole 30 of the loosening prevention nut 100 comes into contact with the tip of the male screw portion 41 of the bolt 40.

  When the loosening prevention nut 100 is further tightened, the hole 30 of the loosening prevention nut 100 tries to advance in the tightening rotation direction without plastic deformation. At this time, the hole diameter of the hole portion 30 of the loosening prevention nut 100 is smaller than the male screw outer diameter 42 of the male screw portion 41 of the bolt 40 to be screwed. Therefore, as shown in FIG. 4, the hole 30 is plastically deformed by embedding the thread 44 of the male thread 41 of the bolt 40 in the thread groove 45. The outer diameter of the outer peripheral surface 46 of the male thread portion 41 of the bolt 40 that has been plastically deformed substantially matches the hole diameter of the hole portion 30 of the loosening prevention nut 100.

  FIG. 5 is a partial development view showing the male thread portion 41 of the bolt 40 according to Embodiment 1 of the present invention. FIG. 6 is a partial development view showing a boundary 47 in which the male thread portion 41 of the bolt 40 according to Embodiment 1 of the present invention is plastically deformed.

  As shown in FIG. 5, before plastic deformation, the thread 44 and the thread groove 45 of the male thread 41 of the bolt 40 are clearly separated so that they can be screwed into the female thread 20 of the loosening prevention nut 100.

  On the other hand, as shown in FIG. 6, when the loosening prevention nut 100 advances in the tightening rotation direction and the hole 30 plastically deforms the thread 44 of the male screw portion 41 of the bolt 40, the male screw portion 41 of the bolt 40 is deformed. The thread 44 and the thread groove 45 form an outer peripheral surface 46 having a substantially constant diameter. That is, as shown by the arrows in FIG. 4, the thread groove 45 of the male thread portion 41 of the bolt 40 that is plastically deformed through the passage 30 of the loosening prevention nut 100 is buried in the plastically deformed screw thread 44. For this reason, the female screw part 20 of the loosening prevention nut 100 cannot be screwed with the male screw part 41 of the plastically deformed bolt 40.

  Thus, after the loosening prevention nut 100 is tightened, the female threaded portion 20 of the loosening prevention nut 100 and the outer peripheral surface 46 which is a plastically deformed portion of the bolt 40 do not mesh. For this reason, the loosening prevention nut 100 cannot return and rotate in the direction opposite to the tightening rotation direction of the bolt 40. In other words, the loosening prevention nut 100 does not loosen due to the return rotation even when the fastened member 50 receives vibration or receives slippage of the fastening portion when rotating.

  Even if the plastically deformed outer peripheral surface 46 of the bolt 40 tries to deform in the loosening direction due to return rotation, the plastically deformed portion of the bolt 40 continues from the boundary 47. Therefore, loosening due to the return rotation of the loosening prevention nut 100 is firmly prevented by the continuously plastically deformed outer peripheral surface 46 of the bolt 40. Alternatively, even if a part of the outer peripheral surface 46 is deformed from the boundary 47, the outer peripheral surface 46 continues from that part. As a result, loosening due to the return rotation of the loosening prevention nut 100 is limited to a minimum. Therefore, it is possible to prevent the loosening due to the return rotation of the loosening prevention nut 100 from getting worse.

According to the first embodiment, the loosening prevention nut 100 includes the female screw portion 20 that is continuous from the opening portion that is opened in the one end surface 21 and that is screwed into the male screw portion 41 of the bolt 40. The loosening prevention nut 100 is provided with a hole 30 that is continuous from an opening that is open to the other end face 31 and that is smaller in diameter than the male thread outer diameter 42 of the male thread 41 of the bolt 40.
According to this configuration, the loosening prevention nut 100 including the female screw portion 20 and the hole portion 30 is attached to the bolt 40 from the female screw portion 20 side, and is tightened and rotated with respect to the bolt 40 to be screwed. In doing so, the thread 44 of the male thread 41 of the bolt 40 is plastically deformed in the hole 30. The plastically deformed male screw portion 41 does not screw into the female screw portion 20 of the loosening prevention nut 100. For this reason, the loosening prevention nut 100 does not rotate in the backward direction of the plastically deformed male screw portion 41. Accordingly, the loosening prevention nut 100 can more firmly prevent loosening due to return rotation.

The center line of the female screw portion 20 and the hole portion 30 coincide with each other.
According to this configuration, the thread 44 of the male threaded portion 41 of the bolt 40 can be plastically deformed by the hole 30 when the nut 40 is tightened and rotated with respect to the bolt 40 to be screwed.

The female screw portion 20 and the hole portion 30 are formed continuously.
According to this configuration, a large force is required for the male screw portion 41 of the bolt 40 to enter the hole portion 30 when the loosening prevention nut 100 is rotated by the user in the tightening rotation direction using a jig. However, when the user plastically deforms the thread 44 of the male threaded portion 41 of the bolt 40 with a great force, the plastically deformed portion is difficult to deform again. Accordingly, the loosening prevention nut 100 can more firmly prevent loosening due to return rotation.

The loosening prevention nut 100 is attached to the bolt 40 from the female screw portion 20 side, and the screw thread 44 of the male screw portion 41 of the bolt 40 is inserted into the hole portion 30 when tightening and rotating with respect to the bolt 40 to be screwed. With plastic deformation.
According to this configuration, the plastically deformed male screw portion 41 does not screw into the female screw portion 20 of the loosening prevention nut 100. For this reason, the loosening prevention nut 100 does not rotate in the backward direction of the plastically deformed male screw portion 41. Accordingly, the loosening prevention nut 100 can more firmly prevent loosening due to return rotation.

The hole 30 plastically deforms the thread 44 of the male threaded portion 41 of the bolt 40 so that the screw groove 45 of the male threaded portion 41 of the bolt 40 is filled, and the male threaded portion 41 of the bolt 40 is replaced with the inner diameter 23 of the female threaded portion 20. The hole diameter is configured to be larger than that.
According to this configuration, the plastically deformed male screw portion 41 is deformed to an outer diameter dimension that is an outer peripheral surface 46 that is not screwed into the female screw portion 20 of the loosening prevention nut 100.

The loosening prevention nut 100 includes a female screw portion 20 that is continuous from an opening portion opened in one end surface 21 and is screwed into a male screw portion 41 of the bolt 40. The loosening prevention nut 100 is provided with a hole 30 that is continuous from an opening that is open to the other end face 31 and that is smaller in diameter than the male thread outer diameter 42 of the male thread 41 of the bolt 40. As a fastening method, the loosening prevention nut 100 is attached to the bolt 40 from the female screw portion 20 side. The fastening method is to plastically deform the thread 44 of the male threaded portion 41 of the bolt 40 at the hole 30 when rotating with respect to the bolt 40 to be screwed.
According to this configuration, the loosening prevention nut 100 has the female screw portion 20 that is screwed into the bolt 40. For this reason, when the loosening prevention nut 100 is fastened to the bolt 40, the loosening prevention nut 100 can rotate in the traveling direction which is the fastening rotation direction. Further, the loosening prevention nut 100 has a hole portion 30 continuous to the female screw portion 20. When the screw 40 is tightened and rotated with respect to the bolt 40, the screw thread 44 of the male screw portion 41 of the bolt 40 is plastically deformed in the hole portion 30. Therefore, the bolt 40 is plastically deformed so as not to be screwed with the female screw portion 20 of the loosening prevention nut 100. Therefore, the loosening prevention nut 100 cannot rotate in the backward direction which is the return rotation direction.
In particular, the force of returning rotation due to vibration of the fastened building part or rotation of the machine part is weaker than the force of plastic deformation of the thread 44 of the male screw part 41 of the bolt 40 at the hole 30. For this reason, the loosening prevention nut 100 does not rotate back and does not deform the outer peripheral surface 46 of the male screw portion 41 of the bolt 40 again. Therefore, the loosening prevention nut 100 can more firmly prevent loosening due to return rotation caused by vibration of a fastened building part or rotation of a machine part.

Embodiment 2. FIG.
FIG. 7 is a cross-sectional view showing a loosening prevention nut 200 according to Embodiment 2 of the present invention. In the second embodiment, a description will be given focusing on differences from the first embodiment.

A loosening prevention nut 200 shown in FIG. 7 includes a female screw part 20, a taper part 60, and a hole part 30.
The female screw portion 20, the taper portion 60, and the hole portion 30 have the same center line extending in the axial direction.
Further, the female screw portion 20 and the hole portion 30 are continuously formed via the taper portion 60.

The taper portion 60 has a conical trapezoidal inner peripheral surface whose diameter decreases from the female screw portion 20 toward the hole portion 30.
The female screw part 20 and the hole part 30 have the same configuration as that of the first embodiment.

The loosening prevention nut 200 having the above-described configuration has a taper portion 60 that is continuous with the female screw portion 20 in a backward direction that is opposite to the tightening rotation direction. The loosening prevention nut 100 has a hole 30 that extends in the axial direction with the same hole diameter continuously to the minimum hole diameter of the tapered portion 60. When the loosening prevention nut 100 is rotated in the tightening rotation direction, the taper portion 60 gradually crushes the thread 44 of the male screw portion 41 of the bolt 40 into a shape not screwed with the female screw portion 20 of the loosening prevention nut 100. Plastically deform. Finally, the hole 30 plastically deforms the thread 44 of the male thread 41 of the bolt 40 to the hole diameter of the hole 30.
For this reason, the force at which the loosening prevention nut 200 is rotated by the user in the tightening rotation direction using a jig may be smaller than when the loosening prevention nut 100 of the first embodiment is rotated.

According to the second embodiment, the female screw portion 20 and the hole portion 30 are continuously formed via the taper portion 60 whose diameter decreases from the female screw portion 20 toward the hole portion 30.
According to this configuration, when passing through the taper portion 60, the thread 44 of the male screw portion 41 of the bolt 40 gradually undergoes plastic deformation to reduce the diameter. For this reason, the force when the loosening prevention nut 200 is rotated by the user in the tightening rotation direction using a jig may be small.

  20 female thread part, 21 end face, 22 thread, 23 inner diameter, 30 hole part, 31 end face, 40 bolt, 41 male thread part, 42 male thread outer diameter, 43 male thread valley diameter, 44 thread thread, 45 thread groove, 46 outer peripheral surface, 47 boundary, 50 fastened member, 51 mounting hole, 60 taper portion, 100 loosening prevention nut, 200 loosening prevention nut.

Claims (7)

A female screw part that is continuous from the opening part that is open on one end face, and is screwed into the male screw part of the mating member;
A hole that is continuous from the opening that opens to the other end face, is smaller in diameter than the male thread outer diameter of the male thread part of the mating member, and is larger in diameter than the male thread valley diameter;
Anti-loosening nut with   The loosening prevention nut according to claim 1, wherein a center line of the female screw portion and the hole portion coincides with each other.   The loosening prevention nut according to claim 1 or 2, wherein the female screw portion and the hole portion are formed continuously.   The loosening prevention nut according to claim 1 or 2, wherein the female screw portion and the hole portion are continuously formed through a taper portion having a diameter that decreases from the female screw portion toward the hole portion.   The screw thread of the male threaded portion of the mating member is plastically deformed in the hole when rotating with respect to the mating member attached and screwed to the mating member from the female screw side. Item 5. The loosening prevention nut according to any one of items 1 to 4.   The hole portion plastically deforms the thread of the male screw portion of the mating member to fill the screw groove of the male screw portion of the mating member, and the male screw portion of the mating member is larger than the inner diameter of the female screw portion. The loosening prevention nut according to claim 5 which is a hole diameter constituted in diameter.   Continuously from the opening opened on one end surface and threadedly engaged with the male threaded portion of the mating member, and continuously from the opening opened on the other end surface, the male threaded portion of the mating member is outside the male thread A loosening prevention nut having a diameter smaller than the diameter and a diameter larger than the male thread valley diameter is attached to the mating member from the female threaded portion side and screwed together. A fastening method in which a screw thread of a male screw portion of the mating member is plastically deformed in the hole portion when rotating with respect to the member.

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