JP2000035025A - Double locking nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the looseness of a double locking nut without damage even external force is applied to a bolt. SOLUTION: A nut material is vertically cut along a surface, having an angle θ larger than a screw lead angle α from a threaded nut material to a surface vertical to the center axis of the nut material, to form upper and lower nuts 1 and 2, and a resin-made adhesive is packed between cut surfaces to keep the continuity of the nut screw groove, thereby adhesively integrating the nuts 1 and 2. The nuts 1 and 2 are integrally fastened to a bolt, and then the nut 1 is turned in a reverse direction to be locked by the abutting part on the nut 2, thereby keeping a whirl-stop condition for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a double locking nut used for fastening a plurality of parts by being inserted into a bolt, and more particularly, to improving the fastening force given at the time of tightening by modifying the nut for a long time. Is to be held over.

[0002]

2. Description of the Related Art Conventionally, as a means for preventing a nut tightened in a bolt from loosening, for example, a double slack nut (see FIG. 4) disclosed in Japanese Patent Publication No. 3-526 is known. . This double slack nut is provided with a convex taper block 6A which is eccentric with a distance δ from the axis of the screw on the upper surface of the lower nut 6, and is concentric with the axis of the screw fitted to the projection of the taper block 6A. Nut 5 with concave portion 5A
Is used. First, the lower nut 6 is fastened to the bolt 7 in the usual manner, and the upper nut 5 is further tightened to prevent loosening of the nut due to a wedge effect at the tapered portion.

[0003]

However, in the above-mentioned double slack nut, the lower nut 6 is tightened and then the upper nut 5 is tightened, so that the double nut is prevented from rotating by the wedge effect at the tapered portion of the lower nut 6. However, when the tightening amount of the upper nut 5 is excessive, since the excessive stress due to the shearing force is generated at the thread root of the bolt due to the horizontal force P applied to the bolt, the bolt is broken when an external force is applied. There is a risk.

An object of the present invention is to propose a double slack nut capable of reliably preventing the nut from loosening without being damaged even when an external force is applied to the bolt.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been obtained by variously devising a locking effect due to a load in the axial direction of a bolt like a commonly used double locking nut, resulting from various efforts. The summary is as follows. The present invention according to claim 1 for achieving the above object is a double locking nut formed by integrating an upper nut and a lower nut, wherein the upper nut and the lower nut are formed from a threaded nut material. It is cut along a surface having an angle larger than the screw lead angle with respect to a surface perpendicular to the center axis of the nut material, and a resin adhesive is filled between the cut surfaces to maintain continuity of the nut screw groove. A double slack nut characterized by being integrally bonded and configured so that the upper nut and the lower nut are integrally turned and fastened to a bolt, and the upper nut is turned in the opposite direction for locking.

According to a second aspect of the present invention, there is provided a double locking nut formed by integrating an upper nut and a lower nut into one body,
The upper nut and the lower nut are formed by cutting a threaded nut material along a surface having an angle larger than a screw lead angle with respect to a surface perpendicular to a central axis of the nut material. The cut including the cut portion is connected and integrated while maintaining the continuity of the nut screw groove, the upper nut and the lower nut are integrally turned, tightened into a bolt, and the upper nut is turned in the opposite direction to lock. A double slack nut characterized by the following.

According to a third aspect of the present invention, the height of the threaded nut material is in a range of 1.2 to 2.0 times the nut thread size diameter. It is. The present invention according to claim 4 is characterized in that the cutting or cutting of the threaded nut material is along a surface having an angle 2 ° to 4 ° larger than the screw lead angle of the nut. Item 1 or 2
It is the double slack nut of description.

According to a fifth aspect of the present invention, there is provided the double slack nut according to the first or second aspect, wherein the width of the cut or cut of the threaded nut material is 0.5 mm or less.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 (a) and (b),
The double slack nut 10 of the present invention uses a threaded nut material having a height higher than that of a normal nut material, and a screw lead angle α = P / (π × d) with respect to a plane perpendicular to the center axis of the nut material.
_The upper nut 1 and the lower nut 2 are formed by vertically cutting or cutting along a plane having an angle θ that is 2 ° to 4 ° larger than ₂ ). Where P: thread pitch,
d ₂ : Indicates the effective screw diameter.

In this manner, the double locking nut 10 is
Long threaded nut material is used for upper nut 1 and lower nut 2
The hexagonal outer size is the same as the JIS nut size. The nut height H, which is the sum of the height of the upper nut 1 and the lower nut 2 and the width t of the cut or cut, is in the range of 1.2 to 2.2 times the thread size diameter d required for the nut strength, that is, H = 1.2. d to 2.0
The screw length is maintained by making d long.

Here, the joint surface between the upper nut 1 and the lower nut 2 is set to an angle θ which is larger by 2 ° to 4 ° than the screw lead angle α. The stopping effect is insufficient, and if it exceeds 4 °, the locking effect becomes too large and the axial force also becomes large. Therefore, in order to ensure an appropriate locking effect, it is appropriate to set the range of 2 ° to 4 °.

The cut width or cut width t of the upper nut 1 and the lower nut 2 is 0.5 mm or less, and a resin adhesive is filled between the cut surfaces to be bonded and integrated, or one corner of the cut portion is formed. Uncut and connected and integrated.
Thereby, the route of the nut screw groove formed by the upper nut 1 and the lower nut 2 maintains continuity, and the upper nut 1 and the lower nut 2 are integrated into one to facilitate screwing into the bolt. The reason why the cutting width or the cutting width t between the upper nut 1 and the lower nut 2 is set to 0.5 mm or less is that if it exceeds 0.5 mm, the locking effect at an arbitrary angle is reduced.

The uncut portion of the cut portion can be easily cut off by turning the upper nut 1. Next, a method of using the double slack nut 10 of the present invention will be described. A double slack nut 10 manufactured with a right-hand screw integrated vertically is screwed into a normal right-hand screw bolt (not shown) set in the bolt hole of the workpiece by clockwise rotation, and the specified torque is applied to the workpiece. Tighten to make tight contact with the seat surface of the material to be fastened to secure fastening axial force.

Subsequently, as shown in FIG. 2A, when the upper nut 1 is turned counterclockwise (locking direction), the upper nut 1 moves upward by a screw pitch corresponding to the rotation angle. . Since the joint surface between the upper nut 1 and the lower nut 2 is divided at an angle θ that is larger than the screw lead angle α by 2 ° to 4 °, the upper nut 1 is turned counterclockwise as shown in FIG. At the stage of rotating by an arbitrary rotation angle, the cut surface of the lower nut 2 and the cut surface of the upper nut 1 are brought into close contact with each other at the competition portion PL, and the locking force Flo is applied between the upper nut 1 and the lower nut 2.
c is secured, and the rotation is stopped.

At the stage where the upper nut 1 is turned counterclockwise, the resin adhesive filling the cut surface at the abutting portion PL between the upper nut 1 and the lower nut 2 is removed by the tightening pressure and hinders the close contact between the two. Never. Alternatively, when an uncut portion is left in one corner of the cut portion in an uncut state, when the upper nut 1 is turned counterclockwise, the uncut portion is removed by rupture and the non-cut portion can be fastened. I do.

FIGS. 3 (a) and 3 (b) show the load state of the thread and the seat surface in the stage of tightening the upper nut 1 and the lower nut 2. FIG. When tightening the upper and lower integrated nut 10,
Of Figure 3 is loaded as the (a) is only under the nut 2 with respect to the fastening member 4, the axial force of the bolt 3 is F _1. On the other hand, when locking the upper nut 1 in the counterclockwise direction, the locking force Floc acts as an internal force between the upper nut 1 and the lower nut 2 as shown in FIG. Since the reaction force between the two is (F ₃ + Floc) and the axial force of the bolt 3 is F ₃ , if the axial force F ₃ is adjusted to an appropriate axial force, the bolt 3 is fastened in a detented state.

[0017]

According to the present invention as described above,
After screwing the upper nut and lower nut together into a double locking nut, simply turn the upper nut in the opposite direction and tighten to secure it to the bolt, ensuring no damage or loosening for a long period of time. , The fastening state is maintained.

[Brief description of the drawings]

FIG. 1 shows the structure of a double locking nut according to the present invention, wherein (a)
FIG. 2 is a plan view, and FIG. 2B is a cross-sectional view showing the direction of arrow AA in FIG.

FIGS. 2A and 2B are explanatory views showing a fastening state of an upper nut and a lower nut forming a double locking nut according to the present invention, wherein FIG. 2A is a plan view, and FIG. 2B is an AA arrow of FIG. It is sectional drawing which shows a viewing direction.

FIG. 3 is an explanatory view showing a load state when an upper nut and a lower nut forming the double slack nut of the present invention are fastened to a workpiece via a bolt by bolts, and (a) is a vertically integrated nut FIG. 7 is a cross-sectional view showing a load state at a stage of attaching the upper nut, and (b) is a cross-sectional view showing a load state at a stage of fastening the upper nut to the lower nut.

FIG. 4 is a sectional view showing a conventional double locking nut.

[Explanation of symbols]

 1,5 Upper nut 2,6 Lower nut 3,7 Bolt 4,8 Workpiece 10 Double release nut

Claims (5)

[Claims] 1. A double slack nut in which an upper nut and a lower nut are integrated into one body, wherein the upper nut and the lower nut extend from a threaded nut material to a surface perpendicular to a center axis of the nut material. It is cut along a surface having an angle larger than the screw lead angle, and is filled with a resin adhesive between the cut surfaces and bonded and integrated while maintaining the continuity of the nut screw groove. Characterized in that the nuts are integrally turned and tightened into bolts, and the upper nut is turned in the opposite direction to lock the nut. 2. A double slack nut in which an upper nut and a lower nut are integrated into one body, wherein the upper nut and the lower nut are formed on a threaded nut material with respect to a surface perpendicular to a central axis of the nut material. The upper nut and the lower nut are cut along a surface having an angle larger than the screw lead angle, and are connected and integrated while maintaining the continuity of the nut screw groove by the cut including a part of the uncut portion. Characterized in that the nuts are integrally turned and tightened into bolts, and the upper nut is turned in the opposite direction to lock the nut. 3. The double slack nut according to claim 1, wherein the height of the threaded nut material is in a range of 1.2 to 2.0 times the nut screw size diameter. 4. The method according to claim 1, wherein the cutting or cutting of the threaded nut material is along a plane having an angle of 2 ° to 4 ° larger than a screw lead angle of the nut. The described double slack nut. 5. The double locking nut according to claim 1, wherein the width of the cut or cut of the threaded nut material is 0.5 mm or less.